StartPage - handle should always return unicode

src/Mod/Start/StartPage/StartPage.py

@@ -472,10 +472,14 @@ def handle():
     Start.iconbank = iconbank
     Start.tempfolder = tempfolder
 
-    # encode if necessary
+    # make sure we are always returning unicode
+    # HTML should be a str-object and therefor:
+    # - for py2 HTML is a bytes object and has to be decoded to unicode
+    # - for py3 HTML is already a unicode object and the next 2 lines can be removed
+    #    once py2-support is removed. 
 
-    if not isinstance(HTML, bytes):
-        HTML = HTML.encode("utf8")
+    if isinstance(HTML, bytes):
+        HTML = HTML.decode("utf8")
     
     return HTML