Python: fix repl workdir

Use the directory that contains the file not the file itself as the
working directory for REPL.

amends 4a42bcd4e8

Change-Id: Ia81efc3ef51a96a79918d358cd446de9f1ea082d
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/python/pythonutils.cpp

@@ -518,7 +518,7 @@ void openPythonRepl(const FilePath &file, ReplType type)
                 return project->projectDirectory();
             return FilePath::fromString(QDir::currentPath());
         }
-        return file;
+        return file.absolutePath();
     };
 
     const auto args = QStringList{"-i"} + replImportArgs(file, type);