Add a scroll area to torrent creator dialog

As to prevent the dialog from going out-of-screen on a small monitor.

src/gui/torrentcreatordialog.ui

@@ -17,6 +17,39 @@
    <string>Torrent Creator</string>
   </property>
   <layout class="QVBoxLayout" name="verticalLayout">
+   <item>
+    <widget class="QScrollArea" name="scrollArea">
+     <property name="frameShape">
+      <enum>QFrame::NoFrame</enum>
+     </property>
+     <property name="widgetResizable">
+      <bool>true</bool>
+     </property>
+     <widget class="QWidget" name="scrollAreaWidgetContents">
+      <property name="geometry">
+       <rect>
+        <x>0</x>
+        <y>0</y>
+        <width>574</width>
+        <height>649</height>
+       </rect>
+      </property>
+      <layout class="QVBoxLayout" name="verticalLayout_5">
+       <property name="spacing">
+        <number>0</number>
+       </property>
+       <property name="leftMargin">
+        <number>0</number>
+       </property>
+       <property name="topMargin">
+        <number>0</number>
+       </property>
+       <property name="rightMargin">
+        <number>0</number>
+       </property>
+       <property name="bottomMargin">
+        <number>0</number>
+       </property>
        <item>
         <widget class="QGroupBox" name="groupBox">
          <property name="title">
@@ -346,6 +379,10 @@
          </layout>
         </widget>
        </item>
+      </layout>
+     </widget>
+    </widget>
+   </item>
    <item>
     <layout class="QHBoxLayout" name="horizontalLayout_2">
      <item>