[libcalamares] Console-logging follows -D flag exactly

- Don't always log LOGEXTRA and below.

src/libcalamares/utils/Logger.cpp

@@ -95,7 +95,7 @@ log( const char* msg, unsigned int debugLevel )
         logfile.flush();
     }
 
-    if ( debugLevel <= LOGEXTRA || debugLevel < s_threshold )
+    if ( logLevelEnabled(debugLevel) )
     {
         QMutexLocker lock( &s_mutex );