Ignore shellcheck errors in admin ssh keys, fix test ssh connection

ssh without -n or </dev/null will eat all input from the while read loop
This stopped the tests in the test ssh connection to be run

see man ssh for the -n option

bin/admin-rotate-ssh-keys.sh

@@ -76,6 +76,7 @@ if [ ! -f "${CONFIG_BASE}settings.ini" ]; then
 	exit;
 fi
 # shellcheck source=../config/settings.ini
+# shellcheck disable=SC1094
 source <(grep "=" "${CONFIG_BASE}settings.ini" | sed 's/ *= */=/g')
 if [ -z "${key_age}" ]; then
 	echo "A minimnum key age in days must be set in the settings";
@@ -124,7 +125,7 @@ fi
 
 # default ssh command
 # -t is needed for systens when "Defaults    requiretty" is set
-SSH="ssh -a -x";
+SSH="ssh -a -x -n";
 
 # Add the SSH Key to an auth file if it does not exist yet and the auth file does exist
 # Build bash command to run this