res_rtp_asterisk: Instead of ./configure use OPENSSL_NO_SRTP.

Previously, Asterisk used its script ./configure, to test whether OpenSSL was
built with no-srtp (or was simply too old). However, the header file
<openssl/opensslconf.h> is the preferred way to detect the local configuration
of OpenSSL.

As a positive side-effect the script ./configure does not interleave the
detection of the Open Settlement Protocol Toolkit (OSPTK) with the detection of
individual features of OpenSSL anymore.

Change-Id: I3c77c7b00b2ffa2e935632097fa057b9fdf480c0

configure

@@ -30763,102 +30763,6 @@ $as_echo "no" >&6; }
 		fi
 	fi
 
-
-if test "x${PBX_OPENSSL_SRTP}" != "x1" -a "${USE_OPENSSL_SRTP}" != "no"; then
-   pbxlibdir=""
-   # if --with-OPENSSL_SRTP=DIR has been specified, use it.
-   if test "x${OPENSSL_SRTP_DIR}" != "x"; then
-      if test -d ${OPENSSL_SRTP_DIR}/lib; then
-         pbxlibdir="-L${OPENSSL_SRTP_DIR}/lib"
-      else
-         pbxlibdir="-L${OPENSSL_SRTP_DIR}"
-      fi
-   fi
-
-      ast_ext_lib_check_save_CFLAGS="${CFLAGS}"
-      CFLAGS="${CFLAGS} "
-      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for SSL_CTX_set_tlsext_use_srtp in -lssl" >&5
-$as_echo_n "checking for SSL_CTX_set_tlsext_use_srtp in -lssl... " >&6; }
-if ${ac_cv_lib_ssl_SSL_CTX_set_tlsext_use_srtp+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_check_lib_save_LIBS=$LIBS
-LIBS="-lssl ${pbxlibdir} -lcrypto $LIBS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char SSL_CTX_set_tlsext_use_srtp ();
-int
-main ()
-{
-return SSL_CTX_set_tlsext_use_srtp ();
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_lib_ssl_SSL_CTX_set_tlsext_use_srtp=yes
-else
-  ac_cv_lib_ssl_SSL_CTX_set_tlsext_use_srtp=no
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_ssl_SSL_CTX_set_tlsext_use_srtp" >&5
-$as_echo "$ac_cv_lib_ssl_SSL_CTX_set_tlsext_use_srtp" >&6; }
-if test "x$ac_cv_lib_ssl_SSL_CTX_set_tlsext_use_srtp" = xyes; then :
-  AST_OPENSSL_SRTP_FOUND=yes
-else
-  AST_OPENSSL_SRTP_FOUND=no
-fi
-
-      CFLAGS="${ast_ext_lib_check_save_CFLAGS}"
-
-
-   # now check for the header.
-   if test "${AST_OPENSSL_SRTP_FOUND}" = "yes"; then
-      OPENSSL_SRTP_LIB="${pbxlibdir} -lssl -lcrypto"
-      # if --with-OPENSSL_SRTP=DIR has been specified, use it.
-      if test "x${OPENSSL_SRTP_DIR}" != "x"; then
-         OPENSSL_SRTP_INCLUDE="-I${OPENSSL_SRTP_DIR}/include"
-      fi
-      OPENSSL_SRTP_INCLUDE="${OPENSSL_SRTP_INCLUDE} "
-
-         # check for the header
-         ast_ext_lib_check_saved_CPPFLAGS="${CPPFLAGS}"
-         CPPFLAGS="${CPPFLAGS} ${OPENSSL_SRTP_INCLUDE}"
-         ac_fn_c_check_header_mongrel "$LINENO" "openssl/ssl.h" "ac_cv_header_openssl_ssl_h" "$ac_includes_default"
-if test "x$ac_cv_header_openssl_ssl_h" = xyes; then :
-  OPENSSL_SRTP_HEADER_FOUND=1
-else
-  OPENSSL_SRTP_HEADER_FOUND=0
-fi
-
-
-         CPPFLAGS="${ast_ext_lib_check_saved_CPPFLAGS}"
-
-      if test "x${OPENSSL_SRTP_HEADER_FOUND}" = "x0" ; then
-         OPENSSL_SRTP_LIB=""
-         OPENSSL_SRTP_INCLUDE=""
-      else
-
-         PBX_OPENSSL_SRTP=1
-         cat >>confdefs.h <<_ACEOF
-#define HAVE_OPENSSL_SRTP 1
-_ACEOF
-
-      fi
-   fi
-fi
-
-
 fi