code maintenance bit to white-list current "You hear" instances

Flag existing occurrences of "You hear" as "Deaf-aware" so
that a grep for that string in the future doesn't need to
trigger further investigation of those.

src/pline.c

@@ -367,7 +367,7 @@ VA_DECL(const char *, line)
     else if (Unaware)
         YouPrefix(tmp, "You dream that you hear ", line);
     else
-        YouPrefix(tmp, "You hear ", line);
+        YouPrefix(tmp, "You hear ", line);  /* Deaf-aware */
     vpline(strcat(tmp, line), VA_ARGS);
     VA_END();
 }