map_series: replaced unordered_set to vector for O(n)

cl_dll/discord_integration.cpp

@@ -30,7 +30,7 @@ namespace discord_integration
 
 		// This list was specially created for a map series, let's say that "hl1_bhop_am" series have a several versions of maps (example: hl1_bhop_am_beta1), but in fact those maps are almost identical
 		// If the beginning of map name matches with what presented in the list, then we set the same name for the thumbnail as in the list (e.g. map name: hl1_bhop_uc1_beta1, thumbnail name: hl1_bhop_uc1)
-		const std::unordered_set<std::string> map_series {
+		const std::vector<std::string> map_series {
 			"hl1_bhop_am"s,
 			"hl1_bhop_bp1"s,
 			"hl1_bhop_bp2"s,