This code tried to automatically generate the X DISPLAY
from the combination of the hostname and display number;
however 127.0.0.1:0 is normally rejected by X11, so this
technique is no good. Fixes dticon hang on startup, caused by
XOpenDisplay failure leading to this message from tttrace:
tt_default_session_set(0x0x875190=="X 127.0.0.1 0") = 1032 (TT_ERR_ACCESS)