Correct format specifiers used to show wxIPV4address.

wxIPV4address::IPAddress() used %lu to show each of (byte-sized) IPv4 address
components for some reason, which resulted in asserts about format specifier
mismatch. Fix this by just using %u.

Closes #12272.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65124 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/sckaddr.cpp

@@ -878,7 +878,7 @@ wxString wxIPV4address::IPAddress() const
 
     return wxString::Format
            (
-            "%lu.%lu.%lu.%lu",
+            "%u.%u.%u.%u",
             (addr >> 24) & 0xff,
             (addr >> 16) & 0xff,
             (addr >> 8) & 0xff,