ui: system config: improve bottom margins and scroll behavior

setting scrollable on the parent tab panel makes not much sense and
will always add a scroll bar that can scroll a few pixels, even if
there's enough space.
Rather set it to true (= auto) in the actual panels that hold the
content.

Also set a bottom margin so that users can see the "end" of the panel
at the bottom, otherwise it looked like it had a start and sides, but
no bottom.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

www/SystemConfiguration.js

@@ -4,7 +4,6 @@ Ext.define('PBS.SystemConfiguration', {
 
     title: gettext('Configuration') + ': ' + gettext('System'),
     border: true,
-    scrollable: true,
     defaults: { border: false },
     tools: [PBS.Utils.get_help_tool("sysadmin-network-configuration")],
     items: [
@@ -18,10 +17,11 @@ Ext.define('PBS.SystemConfiguration', {
 		align: 'stretch',
 		multi: true,
 	    },
+	    scrollable: true,
 	    defaults: {
 		collapsible: true,
 		animCollapse: false,
-		margin: '10 10 0 10',
+		margin: '7 10 3 10',
 	    },
 	    items: [
 		{
@@ -55,10 +55,11 @@ Ext.define('PBS.SystemConfiguration', {
 		align: 'stretch',
 		multi: true,
 	    },
+	    scrollable: true,
 	    defaults: {
 		collapsible: true,
 		animCollapse: false,
-		margin: '10 10 0 10',
+		margin: '7 10 3 10',
 	    },
 	    items: [
 		{