Paper over bug 1054615 by passing sane values to os.utime().

The underlying bug still exists, but also existed in 2.3.4:
import.c's load_source_module() returns NULL if
PyOS_GetLastModificationTime() returns -1, but
PyOS_GetLastModificationTime() doesn't set any exception when it returns
-1, and neither does load_source_module() when it gets back -1.  This
leads to "SystemError: NULL result without error in PyObject_Call"
on an import that fails in this way.
1 file changed