fixed a bug in alert display

lib/utils/action_sheet.dart

@@ -194,17 +194,19 @@ class ActionSheetUtils {
                 Row(
                   mainAxisSize: MainAxisSize.min,
                   children: [
-                    GestureDetector(
-                      onTap: () => Navigator.of(context).pop(),
-                      child: Icon(
-                        data.titleIcon,
-                        size: 20,
-                        color: data.titleColor,
+                    if (data.titleIcon != null)
+                      GestureDetector(
+                        onTap: () => Navigator.of(context).pop(),
+                        child: Icon(
+                          data.titleIcon,
+                          size: 20,
+                          color: data.titleColor,
+                        ),
+                      ),
+                    if (data.titleIcon != null)
+                      const SizedBox(
+                        width: 8,
                       ),
-                    ),
-                    const SizedBox(
-                      width: 8,
-                    ),
                     Expanded(
                       child: DidvanText(
                         data.title!,