remove check on HAVE_SRTP_SHUTDOWN

configure.ac

@@ -1030,7 +1030,6 @@ if test "${srtp_prefix}" != "none" ; then
 	LDFLAGS="$LDFLAGS $SRTP_LIBS"
 	LIBS_save=$LIBS
 	AC_CHECK_LIB(srtp,srtp_init,have_srtp_lib=yes)
-	AC_CHECK_LIB(srtp,srtp_shutdown,[AC_DEFINE([HAVE_SRTP_SHUTDOWN],1,[Defined when srtp_shutdown() exists.])])
 	LDFLAGS=$LDFLAGS_save
 	LIBS=$LIBS_save
 

src/crypto/ms_srtp.c

@@ -299,9 +299,7 @@ err_status_t ms_srtp_init(void)
 void ms_srtp_shutdown(void){
 	srtp_init_done--;
 	if (srtp_init_done==0){
-#ifdef HAVE_SRTP_SHUTDOWN
 		srtp_shutdown();
-#endif
 	}
 }