Fix whitespace (trailing spaces)

CMake/options.cmake

@@ -210,7 +210,7 @@ if (UNIX)
       set (OPTION_USE_WAYLAND 0)
     endif (NOT(DBUS_FOUND AND WLDCLIENT_FOUND AND WLDCURSOR_FOUND AND WLDPROTO_FOUND AND XKBCOMMON_FOUND))
   endif (OPTION_USE_WAYLAND)
-    
+
   if (OPTION_USE_WAYLAND)
     option (OPTION_WAYLAND_ONLY "support Wayland backend only" OFF)
     set (FLTK_USE_WAYLAND 1)

configure.ac

@@ -977,7 +977,7 @@ AS_CASE([$host_os_gui], [cygwin* | mingw*], [
         AC_DEFINE([HAVE_PTHREAD])
         THREADS="threads$EXEEXT"
     ])
-    
+
     AS_IF([test x$enable_wayland != xno], [
       AS_IF([test x$PKGCONFIG = x], [
         dnl pkg-config is not available, issue warning and possibly abort...