Let check.py expect combinations/generate-tasks.py

Author: lembergerth

c/check.py

@@ -119,6 +119,7 @@
     ("eca-rers2018", "unexpected file RERS_18_solutions_dot_petri.csv"),
     ("eca-rers2018", "unexpected file createYml.py"),
     ("nla-digbench-scaling", "unexpected file generate.py"),
+    ("combinations", "unexpected file generate-tasks.py"),
 
     # historical
     ("ntdrivers", "missing readme"),