Consistent junit reporting regardless of internal SECTIONS

Change it so the classname attribute on the <testcase> element is the
test fixture name or "global" regardless of whether the TEST_CASE
contains SECTIONs. This way the output is not changed substantially,
just because a SECTION is added to a TEST_CASE.

include/reporters/catch_reporter_junit.hpp

@@ -139,8 +139,7 @@ namespace Catch {
             std::string className = stats.testInfo.className;
 
             if( className.empty() ) {
-                if( rootSection.childSections.empty() )
-                    className = "global";
+                className = "global";
             }
             writeSection( className, "", rootSection );
         }