Allow ctkThumbnailWidget to be resized with a smaller size

Libs/Widgets/Resources/UI/ctkThumbnailWidget.ui

@@ -11,12 +11,12 @@
    </rect>
   </property>
   <property name="windowTitle">
-   <string>Form</string>
+   <string>Thumbnail</string>
   </property>
   <property name="styleSheet">
    <string notr="true">background-color:white</string>
   </property>
-  <layout class="QVBoxLayout" name="verticalLayout_2">
+  <layout class="QVBoxLayout" name="verticalLayout_2" stretch="0,1">
    <property name="spacing">
     <number>0</number>
    </property>
@@ -31,12 +31,6 @@
        <height>24</height>
       </size>
      </property>
-     <property name="text">
-      <string/>
-     </property>
-     <property name="scaledContents">
-      <bool>false</bool>
-     </property>
      <property name="alignment">
       <set>Qt::AlignCenter</set>
      </property>
@@ -45,14 +39,11 @@
    <item>
     <widget class="QLabel" name="PixmapLabel">
      <property name="sizePolicy">
-      <sizepolicy hsizetype="Expanding" vsizetype="Expanding">
-       <horstretch>128</horstretch>
-       <verstretch>128</verstretch>
+      <sizepolicy hsizetype="Ignored" vsizetype="Preferred">
+       <horstretch>0</horstretch>
+       <verstretch>0</verstretch>
       </sizepolicy>
      </property>
-     <property name="text">
-      <string/>
-     </property>
      <property name="alignment">
       <set>Qt::AlignCenter</set>
      </property>