vendor: update github.com/spf13/cobra to master

vendor/github.com/spf13/cobra/bash_completions.go

@@ -129,7 +129,13 @@ __%[1]s_handle_reply()
     fi
 
     if [[ ${#COMPREPLY[@]} -eq 0 ]]; then
-        declare -F __custom_func >/dev/null && __custom_func
+		if declare -F __%[1]s_custom_func >/dev/null; then
+			# try command name qualified custom func
+			__%[1]s_custom_func
+		else
+			# otherwise fall back to unqualified for compatibility
+			declare -F __custom_func >/dev/null && __custom_func
+		fi
     fi
 
     # available in bash-completion >= 2, not always present on macOS