Backwards compatible with older Qt5

Signed-off-by: falkTX <falktx@gmail.com>

resources/ui/carla_host.ui

@@ -67,16 +67,7 @@
            <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">
+           <property name="margin">
             <number>0</number>
            </property>
            <item>
@@ -239,7 +230,7 @@
      <x>0</x>
      <y>0</y>
      <width>1058</width>
-     <height>30</height>
+     <height>20</height>
     </rect>
    </property>
    <widget class="QMenu" name="menu_File">
@@ -716,7 +707,7 @@
          </layout>
         </widget>
        </widget>
-       <widget class="QTabWidget" name="tabWidget_2">
+       <widget class="QTabWidget" name="tw_miniCanvas">
         <property name="sizePolicy">
          <sizepolicy hsizetype="Minimum" vsizetype="Minimum">
           <horstretch>0</horstretch>
@@ -729,7 +720,7 @@
         <property name="currentIndex">
          <number>0</number>
         </property>
-        <property name="tabBarAutoHide">
+        <property name="tabBarAutoHide" stdset="0">
          <bool>true</bool>
         </property>
         <widget class="QWidget" name="tab_3">
@@ -740,7 +731,7 @@
           </sizepolicy>
          </property>
          <attribute name="title">
-          <string>Tab 1</string>
+          <string/>
          </attribute>
          <layout class="QVBoxLayout" name="verticalLayout_7">
           <property name="spacing">

source/frontend/carla_host.py

@@ -374,7 +374,7 @@ class HostWindow(QMainWindow):
         self.ui.scrollArea.setEnabled(False)
 
         self.ui.miniCanvasPreview.setRealParent(self)
-        self.ui.verticalLayout_7.setContentsMargins(0, 0, 0, 1)
+        self.ui.tw_miniCanvas.tabBar().hide()
 
         # ----------------------------------------------------------------------------------------------------
         # Set up GUI (special stuff for Mac OS)