Reword drowning message so "You <msg>" makes sense

We can't assume that "he" works since that doesn't cover all people. The
sentence also didn't make sense when the user was in single player,
causing "You" to be the beginning of the sentence.

init.lua

@@ -43,7 +43,7 @@ messages.water = {
     " ran out of air.",
     " failed at swimming lessons.",
     " tried to impersonate an anchor.",
-    " forgot he wasn't a fish.",
+    " forgot to breathe.",
     " blew one too many bubbles."
 }