Reverting fix for #444 in order to fix #508

---

Revert "#444: Added type_hint=dialog for the main window to make sure tiling DEs don't affect window position"

This reverts commit 186816c.

data/ui/UlauncherWindow.ui

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!-- Generated with glade 3.22.1 -->
+<!-- Generated with glade 3.18.3 -->
 <interface>
   <requires lib="gtk+" version="3.8"/>
   <requires lib="ulauncher_window" version="1.0"/>
@@ -12,15 +12,11 @@
     <property name="resizable">False</property>
     <property name="window_position">center</property>
     <property name="icon_name">ulauncher</property>
-    <property name="type_hint">dialog</property>
     <property name="skip_taskbar_hint">True</property>
     <property name="skip_pager_hint">True</property>
     <property name="urgency_hint">True</property>
     <property name="decorated">False</property>
     <property name="deletable">False</property>
-    <child>
-      <placeholder/>
-    </child>
     <child>
       <object class="GtkBox" id="body">
         <property name="visible">True</property>
@@ -61,11 +57,10 @@
             <child>
               <object class="GtkButton" id="prefs_btn">
                 <property name="name">prefs_btn</property>
-                <property name="width_request">24</property>
                 <property name="height_request">24</property>
+                <property name="width_request">24</property>
                 <property name="visible">True</property>
                 <property name="can_focus">False</property>
-                <property name="receives_default">False</property>
                 <property name="halign">center</property>
                 <property name="valign">center</property>
                 <property name="margin_right">15</property>