dsv/dsv: delete .zip file if extraction fails

This allows updating a the .zip in cases where the archive's name didn't
change but its content did. "dsv setup" has to be manually re-run in
this case.

dsv/dsv

@@ -80,7 +80,7 @@ flush()
 			# @@@ should handle error
 		fi
 		unzip -p "$DSV_DIR/$zip" "$inside" >"$DSV_DIR/$ds" ||
-		    { rm -f "$DSV_DIR/$ds"; exit 1; }
+		    { rm -f "$DSV_DIR/$zip" "$DSV_DIR/$ds"; exit 1; }
 	fi
     fi
     eval for n in $name $alias\; do \