Shaders: drop an ancient GLSL workaround for Android emulator.

This was added in 2014 in df06a82430 and I
think it's safe to assume this is now fixed in all currently used SDK
versions.

src/Magnum/Shaders/Implementation/CreateCompatibilityShader.h

@@ -61,13 +61,6 @@ inline GL::Shader createCompatibilityShader(const Utility::Resource& rs, GL::Ver
         shader.addSource("#define DISABLE_GL_MAGNUM_shader_vertex_id\n"_s);
     #endif
 
-    /* My Android emulator (running on NVidia) doesn't define GL_ES
-       preprocessor macro, thus *all* the stock shaders fail to compile */
-    /** @todo remove this when Android emulator is sane */
-    #ifdef CORRADE_TARGET_ANDROID
-    shader.addSource("#ifndef GL_ES\n#define GL_ES 1\n#endif\n"_s);
-    #endif
-
     shader.addSource(rs.getString("compatibility.glsl"_s));
     return shader;
 }