Fixed bug 1342 - SDL_CreateRenderer creates OpenGL ES 2.0 renderer in iPhone...

Fixed bug 1342 - SDL_CreateRenderer creates OpenGL ES 2.0 renderer in iPhone 3G using default index (-1)

The uikit code wasn't checking to make sure the context was successfully created.

src/video/uikit/SDL_uikitopengles.m

@@ -115,6 +115,9 @@ SDL_GLContext UIKit_GL_CreateContext(_THIS, SDL_Window * window)
                                     depthBits: _this->gl_config.depth_size
                                     stencilBits: _this->gl_config.stencil_size
                                     majorVersion: _this->gl_config.major_version];
+    if (!view) {
+        return NULL;
+    }
 
     data->view = view;
     view->viewcontroller = data->viewcontroller;

src/video/uikit/SDL_uikitopenglview.m

@@ -75,6 +75,7 @@
         }
         if (!context || ![EAGLContext setCurrentContext:context]) {
             [self release];
+            SDL_SetError("OpenGL ES %d not supported", majorVersion);
             return nil;
         }