Image cropper provides no dimensions in error for single-size configs

When only one size is configured, `smallestSize` is undefined, showing the user an error with blank dimensions.

Author: BurntimeX

ts/WoltLabSuite/Core/Component/Image/Cropper.ts

@@ -357,7 +357,7 @@ class ExactImageCropper extends ImageCropper {
 
     if (sizes.length === 0) {
       const smallestSize =
-        this.configuration.sizes.length > 1 ? this.configuration.sizes[this.configuration.sizes.length - 1] : undefined;
+        this.configuration.sizes.length > 0 ? this.configuration.sizes[this.configuration.sizes.length - 1] : undefined;
       throw new Error(
         getPhrase("wcf.upload.error.image.tooSmall", {
           width: smallestSize?.width,