Merge pull request #2976 from zeromq/revert-2974-static_init_gcc

Revert "Problem: mis-detection of threadsafe_static_init causes test failures"

src/random.cpp

@@ -92,7 +92,8 @@ uint32_t zmq::generate_random ()
 //    configurable via config.h
 
 //  TODO this should probably be done via config.h
-#if (defined(__cpp_threadsafe_static_init)                                     \
+#if __cplusplus >= 201103L                                                     \
+  || (defined(__cpp_threadsafe_static_init)                                    \
       && __cpp_threadsafe_static_init >= 200806)                               \
   || (defined(_MSC_VER) && _MSC_VER >= 1900)
 #define ZMQ_HAVE_THREADSAFE_STATIC_LOCAL_INIT 1