Fix enum compare warning in GuiPanel

[SollyBunny]

warning: enumerated mismatch in conditional expression: ‘GuiControlProperty’ vs ‘GuiDefaultProperty’ [-Wenum-compare]
 1722 |                      GetColor(GuiGetStyle(DEFAULT, (state == STATE_DISABLED)? BASE_COLOR_DISABLED : BACKGROUND_COLOR)));
      |                                                    ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

[raysan5]

@SollyBunny I'm afraid this fix is not correct, GetColor() expects unsigned int.

[SollyBunny]

GetColor(GuiGetStyle(DEFAULT, (state == STATE_DISABLED)? BASE_COLOR_DISABLED : BACKGROUND_COLOR)));
calls
GuiGetStyle(DEFAULT, (state == STATE_DISABLED)? BASE_COLOR_DISABLED : BACKGROUND_COLOR));
where GuiGetStyle is defined as
RAYGUIAPI int GuiGetStyle(int control, int property);
where property is (state == STATE_DISABLED)? BASE_COLOR_DISABLED : BACKGROUND_COLOR which should be an int, both BASE_COLOR_DISABLED (10) and BACKGROUND_COLOR (19) are > 0 in their respective enums and the enums don't contain < 0 elements
static Color GetColor(int hexValue) expects an int but either way I didn't change what type GuiGetStyle returns

I think this is correct

[raysan5]

Reopening for further review...