fix: Settings profile picture

lib/widgets/content_banner.dart

@@ -47,19 +47,12 @@ class ContentBanner extends StatelessWidget {
                 return Hero(
                   tag: heroTag,
                   child: MxcImage(
+                    key: Key(mxContent?.toString() ?? 'NoKey'),
                     uri: mxContent,
                     animated: true,
                     fit: BoxFit.cover,
                     height: 400,
                     width: 800,
-                    placeholder: (c) => Center(
-                      child: Icon(
-                        defaultIcon,
-                        size: 200,
-                        color:
-                            Theme.of(context).colorScheme.onSecondaryContainer,
-                      ),
-                    ),
                   ),
                 );
               }),

lib/widgets/matrix.dart

@@ -492,10 +492,12 @@ class MatrixState extends State<Matrix> with WidgetsBindingObserver {
       if (value != null && int.tryParse(value) != null) {
         AppConfig.colorSchemeSeed = Color(int.parse(value));
         WidgetsBinding.instance.addPostFrameCallback((_) {
-          AdaptiveTheme.of(context).setTheme(
-            light: FluffyThemes.buildTheme(Brightness.light),
-            dark: FluffyThemes.buildTheme(Brightness.dark),
-          );
+          if (mounted) {
+            AdaptiveTheme.of(context).setTheme(
+              light: FluffyThemes.buildTheme(Brightness.light),
+              dark: FluffyThemes.buildTheme(Brightness.dark),
+            );
+          }
         });
       }
     });