[fractal] ui: Remove border_width

[Daniel Garcia Moreno <danigm src gnome org>]

commit 9a09640e728a04f2c884555b0a3fea51894a03cb
Author: Christopher Davis <brainblasted disroot org>
Date:   Sat Oct 31 15:24:52 2020 -0700

    ui: Remove border_width
    
    border_width is gone in GTK4 and can be replaced
    with the margin property.

 fractal-gtk/res/ui/direct_chat.ui     | 18 ------------------
 fractal-gtk/res/ui/invite_user.ui     |  1 -
 fractal-gtk/res/ui/password_dialog.ui |  5 ++++-
 3 files changed, 4 insertions(+), 20 deletions(-)
---
diff --git a/fractal-gtk/res/ui/direct_chat.ui b/fractal-gtk/res/ui/direct_chat.ui
index 84f77587..66a40cf3 100644
--- a/fractal-gtk/res/ui/direct_chat.ui
+++ b/fractal-gtk/res/ui/direct_chat.ui
@@ -18,24 +18,6 @@
       <object class="GtkBox">
         <property name="can_focus">False</property>
         <property name="orientation">vertical</property>
-        <property name="border_width">0</property>
-        <child internal-child="action_area">
-          <object class="GtkButtonBox">
-            <property name="can_focus">False</property>
-            <property name="layout_style">end</property>
-            <child>
-              <placeholder/>
-            </child>
-            <child>
-              <placeholder/>
-            </child>
-          </object>
-          <packing>
-            <property name="expand">False</property>
-            <property name="fill">False</property>
-            <property name="position">0</property>
-          </packing>
-        </child>
         <child>
           <object class="GtkBox">
             <property name="visible">True</property>
diff --git a/fractal-gtk/res/ui/invite_user.ui b/fractal-gtk/res/ui/invite_user.ui
index d7ce2db4..fbe5fef9 100644
--- a/fractal-gtk/res/ui/invite_user.ui
+++ b/fractal-gtk/res/ui/invite_user.ui
@@ -18,7 +18,6 @@
       <object class="GtkBox">
         <property name="can_focus">False</property>
         <property name="orientation">vertical</property>
-        <property name="border_width">0</property>
         <child internal-child="action_area">
           <object class="GtkButtonBox">
             <property name="can_focus">False</property>
diff --git a/fractal-gtk/res/ui/password_dialog.ui b/fractal-gtk/res/ui/password_dialog.ui
index c5fb36a6..80efa2ed 100644
--- a/fractal-gtk/res/ui/password_dialog.ui
+++ b/fractal-gtk/res/ui/password_dialog.ui
@@ -71,7 +71,10 @@
           <object class="GtkBox">
             <property name="visible">True</property>
             <property name="can_focus">False</property>
-            <property name="border_width">6</property>
+            <property name="margin_start">6</property>
+            <property name="margin_end">6</property>
+            <property name="margin_top">6</property>
+            <property name="margin_bottom">6</property>
             <property name="orientation">vertical</property>
             <property name="spacing">6</property>
             <child>