fix: mem box one line to small in gpu build with cpu & net shown and no gpu shown

The fix for the net box shrinking beyond the minimum size for the gpu build
introduced an issue I missed. In the situation where the cpu box is shown,
as well as the net and mem boxes, with no gpus shown. The mem box is one line
to small and because of this the mem graphs are smaller then they should be.

With a gpu shown it looks fine though which also exaggerates the issue with no
gpu shown.

Author: vandabbin

src/btop_draw.cpp

@@ -2381,7 +2381,7 @@ namespace Draw {
 
 			width = round((double)Term::width * (Proc::shown ? width_p : 100) / 100);
 		#ifdef GPU_SUPPORT
-			height = floor(static_cast<double>(Term::height) * (100 - Net::height_p * Net::shown*4 / ((Gpu::shown != 0 and Cpu::shown) + 4)) / 100) - Cpu::height - Gpu::total_height;
+			height = floor(static_cast<double>(Term::height) * (100 - (Net::height_p - (Cpu::shown and Gpu::shown == 0)*6) * Net::shown*4 / ((Gpu::shown != 0 and Cpu::shown) + 4)) / 100) - Cpu::height - Gpu::total_height;
 		#else
 			height = floor(static_cast<double>(Term::height) * (100 - Cpu::height_p * Cpu::shown - Net::height_p * Net::shown) / 100);
 		#endif