Consoles: Don't try to convert debugged filename to unicode if it's a…

…lready in unicode

Fixes #2245

- This error was present only in Python 2
- It was introduced while trying to fix issue #1484

spyderlib/widgets/externalshell/sitecustomize.py

@@ -507,7 +507,10 @@ def postcmd(self, stop, line):
     def break_here(self, frame):
         from bdb import effective
         filename = self.canonic(frame.f_code.co_filename)
-        filename = unicode(filename, "utf-8")
+        try:
+            filename = unicode(filename, "utf-8")
+        except TypeError:
+            pass
         if not filename in self.breaks:
             return False
         lineno = frame.f_lineno