slippery fingers

When the hero has the Glib condition, ^X reports "you have slippery
fingers" or "you have slippery gloves" but self-probing (either wand
or stethoscope aimed at self) was reporting "you have slippery hands."
Change self-probing to match enlightenment for this.

src/insight.c

@@ -2928,7 +2928,7 @@ ustatusline(void)
         Sprintf(eos(info), ", injured %s", what);
     }
     if (Glib)
-        Sprintf(eos(info), ", slippery %s", makeplural(body_part(HAND)));
+        Sprintf(eos(info), ", slippery %s", fingers_or_gloves(TRUE));
     if (u.utrap)
         Strcat(info, ", trapped");
     if (Fast)