Github: rewording application help text strings
Github: rewording application help text strings

Make it clearer what the Github Application Client ID and Secret are
used for.

dregad/source-integration,morgant/source-integration,bright-tools/source-integration-fixes,morgant/source-integration,dregad/source-integration,morgant/source-integration,mantisbt-plugins/source-integration,bright-tools/source-integration-fixes,bright-tools/source-integration,bright-tools/source-integration,make-all/source-integration,mantisbt-plugins/source-integration,mantisbt-plugins/source-integration,bright-tools/source-integration-fixes,bright-tools/source-integration,bright-tools/source-integration,make-all/source-integration,dregad/source-integration,make-all/source-integration