gst-inspect: fix unused-const-variable error in windows
Fix build error in Windows ../tools/gst-inspect.c:44:20: error: 'DEFAULT_PAGER' defined but not used [-Werror=unused-const-variable=]
Fix build error in Windows ../tools/gst-inspect.c:44:20: error: 'DEFAULT_PAGER' defined but not used [-Werror=unused-const-variable=]