Auto update now handles some more obscure situations

Launch plexupdate using "bash plexupdate.sh" will not cause the
autoupdate function to fail anymore. Also tries to handle the error
if it would fail.

plexupdate.sh

@@ -121,7 +121,16 @@ if [ "${AUTOUPDATE}" == "yes" ]; then
 	fi
 	echo "OK"
 	popd >/dev/null
-	$0 ${ALLARGS} -U
+	if ! type "$0" 2>/dev/null >/dev/null ; then
+		if [ -f "$0" ]; then
+			/bin/bash "$0" ${ALLARGS} -U
+		else
+			echo "Error: Unable to relaunch, couldn't find $0"
+			exit 1
+		fi
+	else
+		"$0" ${ALLARGS} -U
+	fi
 	exit $?
 fi