fix layer minZoom being ignored if not less than source maxZoom

This condition led to layers with high minzoom like oneway street
arrows (z15) get parsed and placed regardless of minzoom (e.g. z11+),
wasting a lot of worker CPU time.

It became unnecessary after we added reparsing tiles when overscaling,
and even before that it should have probably been <= rather than <.
Native has the same bug.

cc @jfirebaugh @ansis @kkaefer

js/source/worker_tile.js

@@ -49,7 +49,7 @@ WorkerTile.prototype.parse = function(data, layers, actor, callback) {
             continue;
 
         var minzoom = layer.minzoom;
-        if (minzoom && this.zoom < minzoom && minzoom < this.maxZoom)
+        if (minzoom && this.zoom < minzoom)
             continue;
 
         var maxzoom = layer.maxzoom;