Forces disruptive to be first-rule-only

ModSecurity version 3 is capable to handle disruptive actions in different
rules from the chain. However, lets get it working in the same fashion that
we have in version 2.

src/actions/disruptive/allow.h

@@ -60,6 +60,7 @@ class Allow : public Action {
 
     bool init(std::string *error) override;
     bool evaluate(Rule *rule, Transaction *transaction) override;
+    bool isDisruptive() override { return true; }
 
     AllowType m_allowType;