Strip encrypt file contents

If a newline accidentally gets added to the encrypted content file, it
is unable to be decrypted.

Like the key file, this ensures that the content is stripped of newlines
before decryption.

Author: excid3

activesupport/lib/active_support/encrypted_file.rb

@@ -69,7 +69,7 @@ def key?
     #   decrypted or verified.
     def read
       if !key.nil? && content_path.exist?
-        decrypt content_path.binread
+        decrypt content_path.binread.strip
       else
         raise MissingContentError, content_path
       end