Use older swi prolog 7.5.11 to build YASQE grammar

[kinow]

Related to #190

Using the latest SWIPL for Ubuntu, 9.0.3, results in:

kinow@ranma:~/Development/java/jena/Yasgui/packages/yasqe/grammar$ ./build.sh 
Welcome to SWI-Prolog (threaded, 64 bits, version 9.0.3)
SWI-Prolog comes with ABSOLUTELY NO WARRANTY. This is free software.
Please run ?- license. for legal details.

For online help and background, visit https://www.swi-prolog.org
For built-in help, use ?- help(Topic). or ?- apropos(Word).

ERROR: assertz/1: Type error: `callable' expected, found `[]' (an empty_list)

This PR makes the prolog command pass and the SPARQL grammar to be generated successfully.

Cheers, -Bruno