[tests] update to new WP msg keys

tests/spec/generalized_check.i

 /* run.config
-OPT: -wp -wp-prover qed -wp-msg-key no-cache-info,no-time-info
+OPT: -wp -wp-prover qed -wp-msg-key shell
 OPT: -eva -eva-use-spec f
 OPT: -print
 */

tests/spec/oracle/generalized_check.0.res.oracle

+# frama-c -wp [...]
 [kernel] Parsing tests/spec/generalized_check.i (no preprocessing)
 [wp] Running WP plugin...
 [wp] tests/spec/generalized_check.i:30: Warning: