UI: Make properties window default to 50/50 split

UI/forms/OBSBasicProperties.ui

@@ -32,7 +32,7 @@
       <property name="sizePolicy">
        <sizepolicy hsizetype="Preferred" vsizetype="Expanding">
         <horstretch>0</horstretch>
-        <verstretch>3</verstretch>
+        <verstretch>1</verstretch>
        </sizepolicy>
       </property>
       <property name="frameShape">
@@ -62,7 +62,7 @@
          <property name="sizePolicy">
           <sizepolicy hsizetype="Expanding" vsizetype="Expanding">
            <horstretch>0</horstretch>
-           <verstretch>0</verstretch>
+           <verstretch>1</verstretch>
           </sizepolicy>
          </property>
          <property name="minimumSize">