ux: change MaxHeight of commit message to 64 to ensure that there are at least 2 items displayed in the change list (#66)

Author: love-linger

src/Views/CommitBaseInfo.axaml

@@ -99,7 +99,7 @@
 
           <!-- Messages -->
           <TextBlock Grid.Row="3" Grid.Column="0" Classes="info_label" Text="{DynamicResource Text.CommitDetail.Info.Message}" VerticalAlignment="Top" Margin="0,4,0,0" />
-          <ScrollViewer Grid.Row="3" Grid.Column="1" Margin="12,5,0,0" MaxHeight="100" HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Auto">
+          <ScrollViewer Grid.Row="3" Grid.Column="1" Margin="12,5,0,0" MaxHeight="64" HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Auto">
             <SelectableTextBlock Text="{Binding FullMessage}" FontFamily="{Binding Source={x:Static vm:Preference.Instance}, Path=MonospaceFont}" TextWrapping="Wrap"/>
           </ScrollViewer>
         </Grid>