fix(sdtdserver): restore serverconfig setting (#2640)

lgsm/config-default/config-lgsm/sdtdserver/_default.cfg

@@ -148,6 +148,7 @@ executable=$([ "$(uname -m)" == "x86_64" ] && echo -e "./7DaysToDieServer.x86_64
 servercfgdefault="serverconfig.xml"
 servercfgfullpathdefault="${serverfiles}/${servercfgdefault}"
 servercfgdir="${serverfiles}"
+servercfg="${selfname}.xml"
 servercfgfullpath="${servercfgdir}/${servercfg}"
 
 ## Backup Directory