appsdk-bump-app-catalog 761 bumping sdk to 2440-26c1fd3

sdk commit: RallySoftware/appsdk@6974b4d73d9adb053cea8c5b5d9fcc6f78616251
author: mrampson
message: S68302:added nexus:verify to detect if published archive is bad

sdk commit: RallySoftware/appsdk@26c1fd3fb4cd0a25fcb561c33944ccbb71ebd341
author: David Wire, Will Beard and Dave Thompson
message: S68204: TreeGrid only expands visible nodes