elections2021: Redirect on unknown plan or ministry

elections2021/models.py

@@ -1172,6 +1172,9 @@ class Elections2021ProgramPage(
     @route(r"^plan/([a-z-]+)/$")
     def plan_detail(self, request, param=None):
         plan = param if param in PLAN_OPTIONS else None
+        if not plan:
+            return HttpResponseRedirect(self.url)
+
         title = None
         head_text = ""
         head_image = ""
@@ -1219,6 +1222,9 @@ class Elections2021ProgramPage(
     @route(r"^resort/([a-z-]+)/$")
     def ministry_detail(self, request, param=None):
         ministry = param if param in MINISTRY_OPTIONS else None
+        if not ministry:
+            return HttpResponseRedirect(self.url)
+
         title = None
         head_photo = None