is_numeric: Add defined(X11_t) to checks
Fixes builds of XTS which still builds X11 client side code (unlike libX11 which relies on xcb instead of xtrans now for X11 connections).
Fixes: 0f153064 ("is_numeric: Add TRANS_SERVER to required ifdefs")
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Fixes builds of XTS which still builds X11 client side code (unlike libX11 which relies on xcb instead of xtrans now for X11 connections).
Fixes: 0f153064 ("is_numeric: Add TRANS_SERVER to required ifdefs")