SystemStats: Return just "Windows" or "MacOSX" when operating system version is unknown

modules/juce_core/native/juce_mac_SystemStats.mm

@@ -138,7 +138,7 @@ SystemStats::OperatingSystemType SystemStats::getOperatingSystemType()
         case 13: return MacOS_13;
     }
 
-    return UnknownOS;
+    return MacOSX;
    #endif
 }
 

modules/juce_core/native/juce_win32_SystemStats.cpp

@@ -314,7 +314,7 @@ SystemStats::OperatingSystemType SystemStats::getOperatingSystemType()
     if (major == 5 && minor == 0)      return Win2000;
 
     jassertfalse;
-    return UnknownOS;
+    return Windows;
 }
 
 String SystemStats::getOperatingSystemName()