Don't forget to reset wxSocketImplMac members to NULL.

This avoids an assert in dtor.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@61677 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/osx/core/sockosx.cpp

@@ -75,7 +75,10 @@ private:
         CFSocketInvalidate(m_socket);
 
         CFRelease(m_source);
+        m_source = NULL;
+
         CFRelease(m_socket);
+        m_socket = NULL;
     }
 
     // initialize the data associated with the given socket
@@ -110,6 +113,8 @@ private:
         if ( !m_source )
         {
             CFRelease(m_socket);
+            m_socket = NULL;
+
             return false;
         }