Don't double-place fountains in mammon's level.

There are probably other occurances of this.

dat/gehennom.des

@@ -1515,19 +1515,19 @@ MAP
 1} } }--                 S    |
 2 }   S                  |    |
 3}}}}---------------------    |
-4    |{          ---------- --|
+4    |           ---------- --|
 5 } F--          |........|   |
 6}  F S          |........|   |
 7 }}F --- ---|---|--.--.--|-| |
 8}----|      |                |
-9}||}}|     {|              | |
+9}||}}|      |              | |
 0}||}}|      S             \| |
-1}||}}|     {|              | |
+1}||}}|      |              | |
 2}----|      |                |
 3 }}F --- ---|---|--.--.--|-| |
 4} }F S          |........|   |
 5 }}F--          |........|   |
-6}}}}|{          ---------- --|
+6}}}}|           ---------- --|
 7 }}}---------------------    |
 8}} }}S                  |    |
 9 }} }--                 S    |