Fixes XSS vuln in changeling mimic voice

See https://github.com/tgstation/-tg-station/issues/6975

code/game/gamemodes/changeling/changeling_powers.dm

@@ -657,7 +657,7 @@ var/list/datum/dna/hivemind_bank = list()
 		src << "<span class='notice'>We return our vocal glands to their original location.</span>"
 		return
 
-	var/mimic_voice = input("Enter a name to mimic.", "Mimic Voice", null) as text
+	var/mimic_voice = stripped_input(usr, "Enter a name to mimic.", "Mimic Voice", null, MAX_NAME_LEN)
 	if(!mimic_voice)
 		return
 
@@ -856,4 +856,4 @@ var/list/datum/dna/hivemind_bank = list()
 		changeling.absorbed_species += T.species.name
 
 	feedback_add_details("changeling_powers","ED")
-	return 1
+	return 1