Crash when calling ``GLRenderDevice::draw`` without a bound shader pipeline.

[vyomfadia]

If GLRenderDevice::setShaderPipeline is not called before the GLRenderDevice::draw function, a crash occurs at:

(GLRenderDevice.cpp, Lines 96-102)

void GLRenderDevice::draw(std::size_t first, std::size_t count)
{
    GLShaderPipeline& shader = m_shaders[m_boundShader.get()];
    InputLayout& inputLayout = shader.getInputLayout();

    for (const VertexElement& vertexElement : inputLayout.elements)
    {

This could potentially be fixed by a simple conditional statement, and then just replace the element being iterated over with an empty one temporarily..

[apachano]

@beeperdeeper089 Please add a priority label to this. Thanks!