simplify some logging calls

gallery_dl/extractor/pinterest.py

@@ -243,7 +243,7 @@ class PinterestAPI():
         if response.status_code == 404 or response.history:
             resource = self.extractor.subcategory.rpartition("-")[2]
             raise exception.NotFoundError(resource)
-        self.extractor.log.debug("%s", response.text)
+        self.extractor.log.debug("Server response: %s", response.text)
         raise exception.StopExtraction("API request failed")
 
     def _pagination(self, resource, options):

gallery_dl/extractor/tumblr.py

@@ -156,8 +156,8 @@ class TumblrExtractor(Extractor):
             invalid = types - POST_TYPES
             if invalid:
                 types = types & POST_TYPES
-                self.log.warning('invalid post types: "%s"',
-                                 '", "'.join(sorted(invalid)))
+                self.log.warning("Invalid post types: '%s'",
+                                 "', '".join(sorted(invalid)))
             return types
 
     @staticmethod