Remove wxPropertyGrid property bitmap

This property was present probably because of a copy-paste error.

plugins/additional/xml/data.xml

@@ -422,7 +422,7 @@ Written by
 
   <objectinfo class="wxPropertyGrid" icon="propgrid.xpm" type="propgrid" startgroup="1" wxversion="2904" >
     <inherits class="wxWindow"/>
-    <inherits class="AUI"/> <property name="bitmap" type="bitmap" help="This is the bitmap shown in the default state, it must be always valid while all the other bitmaps are optional and don't have to be set."/>
+    <inherits class="AUI"/>
     <property name="style" type="bitlist">
       <option name="wxPG_AUTO_SORT" help="This will cause Sort() automatically after an item is added. When inserting a lot of items in this mode, it may make sense to use Freeze() before operations and Thaw() afterwards to increase performance."/>
       <option name="wxPG_HIDE_CATEGORIES" help="Categories are not initially shown (even if added)."/>

src/rad/appdata.cpp

@@ -1190,6 +1190,8 @@ void ApplicationData::ConvertObject(tinyxml2::XMLElement* object, int versionMaj
     if (versionMajor < 1 || (versionMajor == 1 && versionMinor < 19)) {
         if (objectClass == "wxStaticBoxSizer") {
             RemoveProperties(object, {"id"});
+        } else if (objectClass == "wxPropertyGrid") {
+            RemoveProperties(object, {"bitmap"});
         } else if (objectClass == "CustomCode") {
             auto properties = GetProperties(object, {
                 "include_cpp", "code_cpp",