Fixup 7ee39bfc1a (include was added to the wrong file)

src/gui/widgets/slider_base.cpp

@@ -22,8 +22,6 @@
 #include "utils/functional.hpp"
 #include "utils/math.hpp"
 
-#include <cstdlib>
-
 #define LOG_SCOPE_HEADER get_control_type() + " [" + id() + "] " + __func__
 #define LOG_HEADER LOG_SCOPE_HEADER + ':'
 

src/utils/math.hpp

@@ -22,6 +22,7 @@
 #include <cmath>
 #include <cstddef>
 #include <cstdint>
+#include <cstdlib>
 #include <limits>
 #include <math.h> // cmath may not provide round()
 #include <vector>