message: Add since to Result enum
diff: <?xml-stylesheet type="text/xml" href="protocol2html.xsl"?>
  <interface name="SmartDeviceLink RAPI" version="5.0.0" minVersion="1.0.0" date="2018-08-17">
  - <enum name="Result" internal_scope="base">
  + <enum name="Result" internal_scope="base" since="1.0">
  <element name="SUCCESS">
  <description>The request succeeded</description>
  </element>
  