title: Mapbox source using TileJSON causing problems on iOS
body: <p>so I have a problem trying to display a map from an internet source with Mapbox using TileJSON.
  I have no problem using a local .mbtiles file or creating an online map using a map ID, but whenever I try to use TileJSON to prevent errors when I don't have network access, I can't seem to load any tile (the map zooming and other gestures are still working though, I can see my annotations and user position).</p>
  
  <p>Here's the code I use to (try) display OpenCycleMaps.</p>
  
  <pre><code>RMMapboxSource *lOnlineTileSource = [[RMMapboxSource alloc] initWithTileJSON: @"{\"tiles\": [ \"http://a.tile.opencyclemap.org/cycle/{z}/{x}/{y}.png\" ], \"minzoom\": 0, \"maxzoom\": 18}"];
  
  [lOnlineTileSource setCacheable:YES];
  
  self.mMapView = [[RMMapView alloc] initWithFrame:self.view.frame andTilesource:lOnlineTileSource];
  </code></pre>
  
  <p>Also, I can see this being logged when I attempt to create a map from the internet with TileJSON:</p>
  
  <pre><code>DB Error: 1 "near "-": syntax error"
  DB Query: PRAGMA cache-size=100
  DB Path: /var/mobile/Containers/Data/Application/A3B998A1-E617-420F-9FBD-1D8396034005/Documents/RMTileCache.db
  </code></pre>
  
  <p>If you could help me figure out what I am doing wrong here, that'd be amazing.</p>