* [admincmd.sma] Fix typo in isCommandArgSafe
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* [admincmd.sma] Update amx_cvar command handler
- Fix exploiting of "mapchangecfgfile" cvar to execute potentially dangerous console commands
- Add newline delimiter check and restrict for ****cfgfile cvars values
* Restrict having ".." character sequence in amx_map command argument
Fixes exploit on Windows servers that allows executing potentially dangerous console commands
* Do not allow admins to change cvars with FCVAR_SPONLY flag when not in singleplayer via amx_cvar
1. Make amx_cvar command obey FCVAR_SPONLY flag.
2. Fix exploiting of amx_nextmap cvar value which is used in nextmap plugin.