fix: fix 'possibly-used-before-assignment' for pylint

.pylintrc

@@ -22,6 +22,7 @@ enable=anomalous-backslash-in-string,
         missing-module-docstring,
         no-else-return,
         no-self-argument,
+        possibly-used-before-assignment,
         redefined-argument-from-local,
         too-few-public-methods,
         trailing-whitespace,

src/wuttjamaican/email.py

@@ -583,13 +583,12 @@ class EmailHandler(GenericHandler):
     def get_auto_body_template(self, key, mode): # pylint: disable=empty-docstring
         """ """
         mode = mode.lower()
-        if mode not in ('txt', 'html'):
-            raise ValueError("requested mode not supported")
-
         if mode == 'txt':
             templates = self.txt_templates
         elif mode == 'html':
             templates = self.html_templates
+        else:
+            raise ValueError("requested mode not supported")
 
         try:
             return templates.get_template(f'{key}.{mode}.mako')