Proactively enable rules instead of only disabling

Previously, rules were enabled by default. Some performance improvements
in draios/sysdig#1126 broke this, requiring that
each rule is explicitly enabled or disabled for a given ruleset.

So if enabled is true, explicitly enable the rule for the default ruleset.

userspace/engine/lua/rule_loader.lua

@@ -449,6 +449,8 @@ function load_rules(rules_content, rules_mgr, verbose, all_events, extra, replac
 
 	 if (v['enabled'] == false) then
 	    falco_rules.enable_rule(rules_mgr, v['rule'], 0)
+	 else
+	    falco_rules.enable_rule(rules_mgr, v['rule'], 1)
 	 end
 
 	 -- If the format string contains %container.info, replace it