appsdk-bump-app-catalog 444 bumping sdk to 1914-d0c762b

sdk commit: RallySoftware/appsdk@333c1613536230cec3ec74acccfecac380af73be
author: Kevin Roberts and Matt Greer
message: Clearing XHR headers if they are not instrumented by client metrics so that they don't keep values from last-instrumented request