another scrambled message when given '-' as object

This is similar to commit 98d381de46
(which mis-classified the bug as post-3.6), using #rub on a lump
of royal jelly and supplying '-' rather than an egg as the target
yielded "You mime rub the royal jellying on something."  Change
it to be "You mime rubbing the royal jelly on something."

doc/fixes37.0

@@ -410,6 +410,8 @@ remove superfluous "All" from "All foos are already nonexistent." when blessed
 	genocide tries to remove something which has already been genocided
 "#dip <item> into -" produced a scrambled message:
 	You mime dip <item> intoing something.
+similarly, "#rub the royal jelly on -" produced
+	You mime rub the royal jellying on something.
 mounted hero falling out of saddle shouldn't hit ground and take damage when
 	levitating or flying (if done without steed's help)
 avoid "obj not free" panic if monster kills itself by reading scroll of earth

src/invent.c

@@ -1427,10 +1427,12 @@ mime_action(const char *word)
         *bp = '\0';
         sfx = (bp + 1); /* "something <sfx>" */
     }
-    if (!strncmp(buf, "dip ", 4) && strstr(buf + 4, " into")) {
-        /* "dip <foo> into" => "dipping <foo> into" */
+    if ((!strncmp(buf, "rub the ", 8) && strstr(buf + 8, " on"))
+        || (!strncmp(buf, "dip ", 4) && strstr(buf + 4, " into"))) {
+        /* "rub the royal jelly on" -> "rubbing the royal jelly on", or
+           "dip <foo> into" => "dipping <foo> into" */
         buf[3] = '\0';
-        pfx = &buf[4]; /* "<pfx> something" */
+        pfx = &buf[3 + 1]; /* "<pfx> something" */
     }
     if ((bp = strstr(buf, " or ")) != 0) {
         *bp = '\0';