SegmentedViewController : add the unreachable homeserver management (i.e. the navbar background color becomes red)

Vector/ViewController/RoomViewController.m

@@ -245,6 +245,9 @@
             MXSession* session = self.roomDataSource.mxSession;
             NSString* roomid = self.roomDataSource.roomId;
             
+            // to display a red navbar when the home server cannot be reached.
+            [segmentedViewController addMatrixSession:session];
+            
             NSMutableArray* viewControllers = [[NSMutableArray alloc] init];
             NSMutableArray* titles = [[NSMutableArray alloc] init];
             
@@ -260,6 +263,7 @@
             [settingsViewController initWithSession:session andRoomId:roomid];
             [viewControllers addObject:settingsViewController];
             
+            
             segmentedViewController.title = NSLocalizedStringFromTable(@"room_details_title", @"Vector", nil);
             [segmentedViewController initWithTitles:titles viewControllers:viewControllers defaultSelected:0];
         }

Vector/ViewController/SegmentedViewController.m

@@ -360,6 +360,10 @@
     [self addConstraint:displayedViewController.view constraint:displayedVCHeightConstraint];
     
     [displayedViewController didMoveToParentViewController:self];
+ 
+    // refresh the navbar background color
+    // to display if the homeserver is reachable.
+    [self onMatrixSessionChange];
 }
 
 #pragma mark - touch event