Don't show overwrite button if invalid paragraph block

Remove the overwrite button in favor of "Attempt Fix" which should
resolve any issues with paragraphs and seems like a better solution to
restore the content verse delete.

Having four buttons to choose from for an invalid block seems like too
much to understand the different options.

editor/components/block-list/invalid-block-warning.js

@@ -42,12 +42,12 @@ function InvalidBlockWarning( { block, attemptFixParagraph, ignoreInvalid, switc
 						{ sprintf( __( 'Attempt Fix' ) ) }
 					</Button>
 				) }
-				<Button
+				{ block.name !== 'core/paragraph' && ( <Button
 					onClick={ ignoreInvalid }
 					isLarge
 				>
 					{ sprintf( __( 'Overwrite' ) ) }
-				</Button>
+				</Button> ) }
 				{ defaultBlockType && (
 					<Button
 						onClick={ switchTo( defaultBlockType ) }