It's 2019, start using new stuff. 1.8.2 will soon be an unsupported version, so there's no point in doing that - simply not worth it. Discord didn't even exist when that version came out.
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Word of advice - maybe a better name for the plugin will be "AMXX Chat Relay". AMX is a very old and no longer supported version of AMXX.
PS: you don't need to include "amxconst" and "cvars" manually - they are already included in "amxmodx".