message: Fall back to creating a non-SRGB capable fbconfig. Refs
  * In some cases it seems that no sRGB fbconfigs are available, so we
  fall back and create a non-SRGB one. This may render incorrectly but
  at least it should run without crashing.
diff: @@ -254,6 +254,8 @@ public:
  RDCERR("Unexpected window system %u", system);
  }
  + // GLX_FRAMEBUFFER_SRGB_CAPABLE_ARB MUST be the last attrib so that we can remove it to retry
  + // if we find no srgb fbconfigs
  static int visAttribs[] = {GLX_X_RENDERABLE,
  True,
  GLX_DRAWABLE_TYPE,
  @@ -273,9 +275,26 @@ public:
  GLX_FRAMEBUFFER_SRGB_CAPABLE_ARB,
  True,
  0};
  +
  int numCfgs = 0;
  GLXFBConfig *fbcfg = glXChooseFBConfig_real(dpy, DefaultScreen(dpy), visAttribs, &numCfgs);
  + if(fbcfg == NULL)
  + {
  + const size_t len = ARRAY_COUNT(visAttribs);
  + if(visAttribs[len - 3] != GLX_FRAMEBUFFER_SRGB_CAPABLE_ARB)
  + {
  + RDCERR(
  + "GLX_FRAMEBUFFER_SRGB_CAPABLE_ARB isn't the last attribute, and no SRGB fbconfigs were "
  + "found!");
  + }
  + else
  + {
  + visAttribs[len - 3] = 0;
  + fbcfg = glXChooseFBConfig_real(dpy, DefaultScreen(dpy), visAttribs, &numCfgs);
  + }
  + }
  +
  if(fbcfg == NULL)
  {
  RDCERR("Couldn't choose default framebuffer config");
  