Qt4: remove (no-)sout-keep option

This is not really relevant as long as we have only one item.
However, sout-keep should really always be on anyway when streaming.
Most protocols would terminate client connections when the item
changes, and the file output would overwrite the file.

(sout_gather would be more problematic. We should use it too, but it
has always made sout_display crash.)

modules/gui/qt4/dialogs/sout.cpp

@@ -87,7 +87,7 @@ SoutDialog::SoutDialog( QWidget *parent, intf_thread_t *_p_intf, const QString&
 #define CC( x ) CONNECT( ui.x, currentIndexChanged( int ), this, updateMRL() );
 
     /* Misc */
-    CB( soutAll ); CB( soutKeep );  CS( ttl ); CT( sapName ); CT( sapGroup );
+    CB( soutAll );  CS( ttl ); CT( sapName ); CT( sapGroup );
     CB( localOutput );
     CONNECT( ui.profileSelect, optionsChanged(), this, updateMRL() );
 
@@ -261,7 +261,7 @@ void SoutDialog::updateMRL()
 
     if( ui.soutAll->isChecked() )  mrl.append( " :sout-all" );
 
-    if( ui.soutKeep->isChecked() ) mrl.append( " :sout-keep" );
+    mrl.append( " :sout-keep" );
 
     ui.mrlEdit->setPlainText( mrl );
 }

modules/gui/qt4/ui/sout.ui

@@ -289,20 +289,13 @@
           <string>Miscellaneous Options</string>
          </property>
          <layout class="QGridLayout" name="gridLayout_4">
-          <item row="0" column="0" colspan="3">
+          <item row="0" column="0" colspan="5">
            <widget class="QCheckBox" name="soutAll">
             <property name="text">
              <string>Stream all elementary streams</string>
             </property>
            </widget>
           </item>
-          <item row="0" column="3" rowspan="2" colspan="2">
-           <widget class="QCheckBox" name="soutKeep">
-            <property name="text">
-             <string>Keep stream output open</string>
-            </property>
-           </widget>
-          </item>
           <item row="1" column="0" rowspan="2">
            <widget class="QCheckBox" name="sap">
             <property name="text">