use temaki-paifang icon for Paifang preset (#1767)

Author: novolife

data/presets/man_made/ceremonial_gate/paifang.json

@@ -1,5 +1,5 @@
 {
-    "icon": "roentgen-city_gate",
+    "icon": "temaki-paifang",
     "fields": [
         "{man_made/ceremonial_gate}"
     ],