loadFonts to check if there is a logger when debug==True

For the following use case:
UFOProcessor object is initialised with `debug=False`, no logger is started.
Then, in a scripted context, the debug flag is set to True. But this is just an attribute, so there is no logger.
Then `loadFonts` checks both `debug` and `logger` and calls `startLog` to create one if needed.

Lib/ufoProcessor/ufoOperator.py

@@ -399,6 +399,11 @@ def getAxis(self, axisName):
     # loading and updating fonts
     def loadFonts(self, reload=False):
         # Load the fonts and find the default candidate based on the info flag
+        if self.logger is None and self.debug:
+            # in some cases the UFOProcessor is initialised without debug
+            # and then it is switched on afterwards. So have to check if
+            # we have a logger before proceding. 
+            self.startLog()
         self.glyphNames = list({glyphname for font in self.fonts.values() for glyphname in font.keys()})
         if self._fontsLoaded and not reload:
             if self.debug:
@@ -1761,8 +1766,12 @@ def _copyFontInfo(self, sourceInfo, targetInfo):
     if ds5Path is None:
         doc = UFOOperator()
     else:
-        doc = UFOOperator(ds5Path, useVarlib=True, debug=debug)
+        doc = UFOOperator(ds5Path, useVarlib=True, debug=False)
+        print("Initialised without debug, no logger:", doc.logger)
+        doc.debug=True
+        print("Set debug to True, after initialisation:", doc.debug)
         doc.loadFonts()
+        print("loadFonts checks and creates a logger if needed:", doc.logger)
 
 
     # test the getLibEntryMutator