Replaces CMGSV with CLSV in factions.dm (#4220)

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## Why It's Good For The Game
Both Arke and Vela use that one, and it's not in the file. CMGSV is not
really used anymore (it was used by the old Vela).
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## Changelog

:cl:
code: Replaced the CMGSV prefix with CLSV.
/:cl:

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code/__DEFINES/factions.dm

@@ -37,7 +37,7 @@
 #define PREFIX_SOLGOV list("SCSV")
 #define PREFIX_SRM list("SRSV")
 #define PREFIX_INTEQ list("IRMV")
-#define PREFIX_CLIP list("CMSV", "CMGSV")
+#define PREFIX_CLIP list("CMSV", "CLSV")
 #define PREFIX_NT list("NTSV")
 	#define PREFIX_NS_LOGI list("NSSV")
 	#define PREFIX_VIGILITAS list("VISV")