Fixed OpenGL ES 1.1 on Android

From Gabriel Jacobo:
What I did notice is that calling
data->glGetIntegerv(GL_FRAMEBUFFER_BINDING_OES, &value); doesn't produce any
result in Android GLES1.1 if the active framebuffer is the default one, ie,
whatever is in value stays unmodified.

src/render/opengles/SDL_render_gles.c

@@ -349,15 +349,18 @@ GLES_CreateRenderer(SDL_Window * window, Uint32 flags)
     }
 #endif
 
+    value = 0;
     data->glGetIntegerv(GL_MAX_TEXTURE_SIZE, &value);
     renderer->info.max_texture_width = value;
+    value = 0;
     data->glGetIntegerv(GL_MAX_TEXTURE_SIZE, &value);
     renderer->info.max_texture_height = value;
 
     if (SDL_GL_ExtensionSupported("GL_OES_framebuffer_object")) {
         data->GL_OES_framebuffer_object_supported = SDL_TRUE;
         renderer->info.flags |= SDL_RENDERER_TARGETTEXTURE;
 
+        value = 0;
         data->glGetIntegerv(GL_FRAMEBUFFER_BINDING_OES, &value);
         data->window_framebuffer = (GLuint)value;
     }