Don't ask for upstream host/port for master instances.

Refs #6002

pki/icinga2-setup-agent.cmake

@@ -87,6 +87,9 @@ if [ -n "$1" ]; then
 		fi
 	fi
 
+	upstream_connect=n
+
+	if [ "$master" = "n" ]; then
 		while true; do
 			echo -n "Do you want this agent instance to connect to the upstream instance? [y] "
 			if ! read upstream_connect; then
@@ -131,6 +134,7 @@ if [ -n "$1" ]; then
 				echo "Please enter the upstream instance's port."
 			done
 		fi
+	fi
 
 	echo "Installing the certificate bundle..."
 	base64 -d < $1 | tar -C $ICINGA2CONFIG/pki/agent/ -zx || exit 1