Add patch to raw email for edge case issue

Fixes issue where spaces are included before some email headers.

See mysociety/asktheeu-theme#120
See mysociety/alaveteli#6853

lib/model_patches.rb

@@ -86,6 +86,18 @@ def is_school?
     end
   end
 
+  RawEmail.class_eval do
+    alias original_data data
+
+    def data
+      original_data.sub(/
+        ^(Date: [^\n]+\n)
+        \s+(To: [^\n]+\n)
+        \s+(From: [^\n]+)
+      /x, '\1\2\3')
+    end
+  end
+
   ReplyToAddressValidator.invalid_reply_addresses = %w(
     [email protected]
     [email protected]