x11/shotman: unbreak build after ebf29acc6ce4

> Checking for pkg-plist issues (check-plist)

> Parsing plist

> Checking for items in STAGEDIR missing from pkg-plist

> Checking for items in pkg-plist which are not in STAGEDIR

Error: Missing: bin/shotman_completions

> Error: Plist issues found.

• Error code 1