remove dead link to SUSv4 interface table document

Author: vladak

intro.tex

@@ -197,8 +197,7 @@
 \item The interface groups of POSIX together with the Xcurses group, are part
 of the Single Unix Specification (however not part of POSIX base in the IEEE Std
 1003.1-2001 standard) which includes 1833 interfaces in total, which form the Single Unix
-Specification (SUSv4, 2018). The SUSv4 interface tables are here:
-\url{https://unix.org/version4/GS5\_APIs.pdf}
+Specification (SUSv4, 2018).
 \item Commercial UNIXes largely follow the Single UNIX Specification, compliance
 to this standard is the condition to use the UNIX trademark
 (the UNIX 98 brand corresponds to SUSv2, UNIX 03 corresponds to SUSv3, SUSv4 is