Do not fail on asserts for added property model

For example, here is description of sleep:common property:

              {
                "name": "TR",
                "options": {"templates": [
                  "linux/kernel/locking/spinlock.c.tmpl",
                  "linux/kernel/locking/spinlock.aspect.tmpl"
                ]}
              },
              {
                "name": "RSG",
                "options": {"models": [
                  {
                    "model": "$linux/kernel/locking/spinlock.c",
                    "options": {"sets model": "flag"}
                  },
                  "linux/kernel/locking/rwlock.c",
                  "linux/sleep/common.c"
                ]}

and its unsafes include asserts for spinlock property.