Catch IOError when a query times out and retry correctly

[goodlyrottenapple]

This (hopefully) fixes runtimeverification/k#3729, specifially the error below, thrown here

kore-exec: [41516716] Error (ErrorException):
    user error (Unexpected result from the SMT solver:
      Command: (push 1 )
      Expected: success
      Result: (error "line 178 column 8: push canceled" )
    )

This error occurs when smt-limit is low and we send an assert query to the solver. When this happens, we want to re-try instead of letting the error bubble up, as it currently does.

I have tested this and confirmed that at a threshold level of smt-timeout where Z3 fails intermittently, with this change, we re-try the specified number of times before failing fully.

[jberthold]

LGTM. Good job tracking this down!