Refactor the structure of expressions in where blocks of filter bitdefender_gz.

Author: JocLRojas

filters/antivirus/bitdefender_gz.yml

@@ -1,4 +1,4 @@
-# Bitdefender GravityZone filter
+# Bitdefender GravityZone filter, version 3.0.1
 # Based on https://www.bitdefender.com/business/support/en/77212-237089-event-types.html
 # and the previous version of the same filter
 
@@ -233,12 +233,7 @@ pipeline:
           params:
             source: origin.ip
             destination: origin.geolocation
-          where:
-            variables:
-              - get: origin.ip
-                as: oIp
-                oftype: string
-            expression: oIp_ok==true
+          where: has(origin.ip)
 
       # Reformat and field conversions
       - cast: