Remove unnecessary branch in urlsafe_decode64 in column_encryption pl…

…ugin

Sequel always generates the base64 with = padding, so we don't need
to check for unpadded base64 and adjust.

lib/sequel/plugins/column_encryption.rb

@@ -490,13 +490,7 @@ def urlsafe_encode64(bin)
  end
 
  def urlsafe_decode64(str)
- if str.length % 4 == 0
- str = str.tr("-_", "+/")
- else
- str = str.ljust((str.length + 3) & ~3, "=")
- str.tr!("-_", "+/")
- end
- decode64(str)
+ decode64(str.tr("-_", "+/"))
  end
 
  # An array of strings, one for each configured encryption key, to find encypted values matching