BaseTools: Fix Python SyntaxWarning

- Windows paths must be escaped
- Regex should use raw strings

Signed-off-by: Tim Crawford <tcrawford@system76.com>

BaseTools/Source/Python/Ecc/Configuration.py

@@ -435,7 +435,7 @@ class Configuration(object):
 # test that our dict and out class still match in contents.
 #
 if __name__ == '__main__':
-    myconfig = Configuration("BaseTools\Source\Python\Ecc\config.ini")
+    myconfig = Configuration("BaseTools\\Source\\Python\\Ecc\\config.ini")
     for each in myconfig.__dict__:
         if each == "Filename":
             continue