uitest: fix path to url conversion on windows

Our windows path is stored e.g. as D:/libo1 which os.path.path2url converts to D://libo1.
UNO does not recognize the URL as a valid file URL.

Change-Id: Iad4c4a3944d26312bb79bfeefaf55f697c0afd1c

uitest/uitest/path.py

@@ -14,7 +14,7 @@ def get_src_dir_fallback():
     return os.path.abspath(os.path.join(current_dir, "../../"))
 
 def path2url(path):
-        return urljoin('file:', pathname2url(path))
+        return urljoin('file:', pathname2url(os.path.normpath(path)))
 
 def get_workdir_url():
     workdir_path = os.environ.get('WORKDIR', os.path.join(get_src_dir_fallback(), 'workdir'))