Update persian merchant ship mesh to reduce the amount of transparency.

This was SVN commit r23440.

binaries/data/mods/public/art/actors/props/structures/persians/merchant_rail.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<actor version="1">
+  <castshadow/>
+  <float/>
+  <group>
+    <variant frequency="100" name="Base">
+      <mesh>structural/pers_merc_rail.dae.dae</mesh>
+      <props>
+        <prop actor="props/structures/persians/merchant_sail.xml" attachpoint="root"/>
+      </props>
+      <textures>
+        <texture file="structural/pers_merc.dds" name="baseTex"/>
+      </textures>
+    </variant>
+  </group>
+  <material>basic_trans.xml</material>
+</actor>

binaries/data/mods/public/art/actors/structures/persians/merchant.xml

@@ -7,9 +7,12 @@
       <mesh>structural/pers_merc.dae</mesh>
       <props>
         <prop actor="props/structures/persians/merchant_sail.xml" attachpoint="root"/>
+        <prop actor="props/structures/persians/merchant_rail.xml" attachpoint="root"/>
       </props>
-      <textures><texture file="structural/pers_merc.dds" name="baseTex"/></textures>
+      <textures>
+        <texture file="structural/pers_merc.dds" name="baseTex"/>
+      </textures>
     </variant>
   </group>
-  <material>basic_trans.xml</material>
+  <material>default.xml</material>
 </actor>