Kivy: Fix MessageBox popups (#5193)

data/client.kv

@@ -220,6 +220,8 @@
 <MessageBoxLabel>:
     theme_text_color: "Custom"
     text_color: 1, 1, 1, 1
+<MessageBox>:
+    height: self.content.texture_size[1] + 80
 <ScrollBox>:
     layout: layout
     bar_width: "12dp"
@@ -233,8 +235,3 @@
         spacing: 10
         size_hint_y: None
         height: self.minimum_height
-<MessageBoxLabel>:
-    valign: "middle"
-    halign: "center"
-    text_size: self.width, None
-    height: self.texture_size[1]

kvui.py

@@ -720,13 +720,11 @@ class MessageBoxLabel(MDLabel):
 
 
 class MessageBox(Popup):
-
     def __init__(self, title, text, error=False, **kwargs):
-        label = MessageBoxLabel(text=text)
+        label = MessageBoxLabel(text=text, padding=("6dp", "0dp"))
         separator_color = [217 / 255, 129 / 255, 122 / 255, 1.] if error else [47 / 255., 167 / 255., 212 / 255, 1.]
         super().__init__(title=title, content=label, size_hint=(0.5, None), width=max(100, int(label.width) + 40),
                          separator_color=separator_color, **kwargs)
-        self.height += max(0, label.height - 18)
 
 
 class MDNavigationItemBase(MDNavigationItem):