Fix FFGLFBO::Release leaking the color texture

[stoatworks-labs]

FFGLFBO::Release() has two consecutive blocks guarded on depthBufferID:

if( depthBufferID != 0 )
{
    glDeleteRenderbuffers( 1, &depthBufferID );
    depthBufferID = 0;
}

if( depthBufferID != 0 )
{
    glDeleteTextures( 1, &depthBufferID );
    depthBufferID = 0;
}

The first block zeroes depthBufferID, so the second is unreachable. It was
plainly meant to test and delete colorTextureID, which is therefore never
deleted — every FFGLFBO release leaks one texture.

That matters in practice because Initialise() calls Release() on its own
failure paths, and plugins that keep FBOs for intermediate passes release and
re-initialise them on every resolution change. The leaked textures are
full-size render targets, so it adds up over a session.

The fix is the three-line change to the second condition. No behaviour changes
beyond the texture now being deleted; if colorTextureID is already 0 the block
is skipped exactly as before.

🤖 Generated with Claude Code