Fix typo in systemd service

init/postsrsd.systemd.in

 
 [Service]
 Type=simple
-Environment SRS_DOMAIN=localhost.localdomain
-Environment SRS_EXCLUDE_DOMAINS=
+Environment=SRS_DOMAIN=localhost.localdomain
+Environment=SRS_EXCLUDE_DOMAINS=
 EnvironmentFile=@CONFIG_DIR@/@PROJECT_NAME@
 ExecStart=@CMAKE_INSTALL_PREFIX@/sbin/@POSTSRSD@ -f${SRS_FORWARD_PORT} -r${SRS_REVERSE_PORT} -d${SRS_DOMAIN} -s${SRS_SECRET} -u${RUN_AS} -c${CHROOT} -X${SRS_EXCLUDE_DOMAINS}
 Restart=always