move return up into #ifdef.

src/zm_rtsp_auth.cpp

@@ -201,8 +201,8 @@ std::string Authenticator::computeDigestResponse(std::string &method, std::strin
     return md5HexBuf;
 #else // HAVE_DECL_MD5
 	Error( "You need to build with gnutls or openssl installed to use digest authentication" );
-#endif // HAVE_DECL_MD5
     return( 0 );
+#endif // HAVE_DECL_MD5
 }
 
 void Authenticator::checkAuthResponse(std::string &response) {