disable transforms from image trace

Author: etpinard

src/traces/image/attributes.js

@@ -114,5 +114,7 @@ module.exports = extendFlat({
     }),
     hovertemplate: hovertemplateAttrs({}, {
         keys: ['z', 'color', 'colormodel']
-    })
+    }),
+
+    transforms: undefined
 });

src/traces/image/defaults.js

@@ -35,4 +35,6 @@ module.exports = function supplyDefaults(traceIn, traceOut) {
     coerce('text');
     coerce('hovertext');
     coerce('hovertemplate');
+
+    traceOut._length = null;
 };