Server should be stopped during mods-update

From the SourceMod Wiki: [Upgrading SourceMod](https://wiki.alliedmods.net/Upgrading_SourceMod)

> Ensure your game server is completely stopped and not running as you cannot update some files while they are still in use.

Running: `./csgoserver mods-update`
```
csgoserver@dellserver:~$ ./csgoserver mods-update
[ INFO ] Mods Update csgoserver: Update addons/mods: 2 addons/mods will be updated
* MetaMod (retain common custom files)
* SourceMod (retain common custom files)

==> Updating MetaMod
creating mod download directory /home/csgoserver/lgsm/mods/tmp...OK
######################################################################## 100.0%it966-linux.tar.gz...
OK
extracting mmsource-1.10.7-git966-linux.tar.gz...OK
the following files/directories will be preserved:
* serverfiles/addons/metamod/metaplugins.ini
building metamod-files.txt...OK
copying MetaMod to /home/csgoserver/serverfiles/csgo...OK
tidy up metamod-files.txt...OK
clearing mod download directory /home/csgoserver/lgsm/mods/tmp...OK

==> Updating SourceMod
creating mod download directory /home/csgoserver/lgsm/mods/tmp...OK
######################################################################## 100.0%git6260-linux.tar.gz...
OK
extracting sourcemod-1.9.0-git6260-linux.tar.gz...OK
the following files/directories will be preserved:
* serverfiles/cfg
* serverfiles/addons/sourcemod/configs
building sourcemod-files.txt...OK
copying SourceMod to /home/csgoserver/serverfiles/csgo...OK
tidy up sourcemod-files.txt...OK
clearing mod download directory /home/csgoserver/lgsm/mods/tmp...OK

[ OK ] Mods Update csgoserver: Mods update complete
```

**Expected behaviour**
A server should be stopped during mods-update, and restart after it's finished.

**Additional context**
`mods-update` is updating the mods regardless the version installed. It's updating even an updated version as well.