Minor fixes to new wxLog functions test case

Only use the diagnostic pragma for the compilers that understand it.

Also don't use hard TABs.

tests/log/logtest.cpp

@@ -397,9 +397,12 @@ void LogTestCase::NoWarnings()
 // The following two functions (v, macroCompilabilityTest) are not run by
 // any test, and their purpose is merely to guarantee that the wx(V)LogXXX
 // macros compile without 'dangling else' warnings.
-#pragma GCC diagnostic error "-Wdangling-else"
+#if defined(__clang__) || wxCHECK_GCC_VERSION(4, 6)
+    #pragma GCC diagnostic error "-Wdangling-else"
+#endif
 
-static void v(int x, ...) {
+static void v(int x, ...)
+{
     va_list list;
     va_start(list, x);