Fix image load

Examples/Tests/index.ios.js

@@ -19,7 +19,7 @@ const Tests = React.createClass({
       <HelloGL width={64} height={64} />;
 
     const txt =
-      <View style={{ width: 800, height: 800, position: "relative" }}>
+      <View style={{ width: 800, height: 800, position: "relative", backgroundColor: "transparent" }}>
         {[0,1,2,3].map(i => <Text style={{
           position: "absolute",
           top: 40+200*i,

RNGL/GLCanvas.m

@@ -144,7 +144,7 @@ NSString* srcResource (id res)
             }
             if (image == nil) {
               image = [[GLImage alloc] initWithBridge:_bridge withOnLoad:^{
-                [self setNeedsDisplay];
+                [self requestSyncData];
               }];
               image.src = src;
               images[src] = image;