Fix abigen not supporting enhanced privacy for go #1103

Job	Run time
Code linters	3m 28s
Build Docker image	2m 32s
Unit tests in ubuntu-20.04	28m 5s
Run PEEPS tests	9m 39s
Acceptance tests (basic \|\| basic-raft \|\| (advanced && raft) \|\| networks/typical::raft)	19m 20s
Acceptance tests (basic \|\| basic-istanbul \|\| (advanced && istanbul && !block-heights) \|\| networks/typical::istanbul)	23m 28s
Acceptance tests (basic \|\| basic-istanbul \|\| (advanced && istanbul && !block-heights) \|\| empty-block-period \|\| block-reward \|\| networks/typical::qbft)	22m 7s
Acceptance tests (validator-management && networks/template::istanbul-3plus1)	9m 49s
Acceptance tests (validator-management && networks/template::qbft-3plus1)	8m 54s
Acceptance tests (multitenancy && networks/plugins::raft-multitenancy)	50s
Acceptance tests (migration && networks/template::istanbul-4nodes)	6m 42s
Acceptance tests (migration && networks/template::raft-4nodes)	5m 6s
Acceptance tests (basic \|\| networks/typical::raftmps)	16m 56s
Acceptance tests (basic \|\| networks/typical::istanbulmps)	22m 36s
Acceptance tests (basic \|\| networks/typical::qbftmps)	21m 21s
	3h 20m 53s

Provide feedback