fix (arma3server): prevent multiple loading mods failing due to accidental line termination (#3845)

Fixes loading multiple mods failing due to accidental line termination in the mod string when following the documentation. (Observed on Ubuntu 20.10)

lgsm/config-default/config-lgsm/arma3server/_default.cfg

@@ -32,7 +32,7 @@ servermods=""
 bepath=""
 
 ## Server Parameters | https://docs.linuxgsm.com/configuration/start-parameters#additional-parameters
-startparameters="-ip=${ip} -port=${port} -cfg=${networkcfgfullpath} -config=${servercfgfullpath} -mod=${mods} -servermod=${servermods} -bepath=${bepath} -autoinit -loadmissiontomemory"
+startparameters="-ip=${ip} -port=${port} -cfg=${networkcfgfullpath} -config=${servercfgfullpath} -mod='${mods}' -servermod=${servermods} -bepath=${bepath} -autoinit -loadmissiontomemory"
 
 #### LinuxGSM Settings ####