Support MYSQLD_OPTS and _WSREP_NEW_CLUSTER env vars in init script, same as it is done in case of systemd unit file

Related: #1455850

mariadb.spec

@@ -1624,6 +1624,9 @@ fi
 %changelog
 * Thu Jan 11 2018 Honza Horak <hhorak@redhat.com> - 3:10.2.12-1
 - Do not build connect plugin with mongo and jdbc connectors
+- Support MYSQLD_OPTS and _WSREP_NEW_CLUSTER env vars in init script,
+  same as it is done in case of systemd unit file
+  Related: #1455850
 
 * Wed Jan 10 2018 Michal Schorm <mschorm@redhat.com> - 3:10.2.12-1
 - Rebase to 10.2.12

mysql.init.in

@@ -82,7 +82,7 @@ start(){
 	# Note: set --basedir to prevent probes that might trigger SELinux
 	# alarms, per bug #547485
 	su - $MYUSER -s /bin/bash -c "$exec   --datadir='$datadir' --socket='$socketfile' \
-		--pid-file='$pidfile' \
+		--pid-file='$pidfile' $MYSQLD_OPTS $_WSREP_NEW_CLUSTER \
 		--basedir=@prefix@ --user=$MYUSER" >/dev/null 2>&1 &
 	safe_pid=$!