*: Remove nil check from setters

[fyrchik]

Close #388 .

I knew one day sed would save me an hour of manual work:

sed -i -n -e '
s/) Set/) Set/
p
t setter
b end
:setter
    n
    s/nil/nil/
    t hasif
    p
    b end
    :hasif
        n
        :loop
        p
        n
        s/}/}/
        t end
        b loop
        :end
' $@
goimports -w $@

Signed-off-by: Evgenii Stratonikov evgeniy@nspcc.ru

[codecov]

Codecov Report

Merging #388 (3869910) into master (5016274) will decrease coverage by 1.06%.
The diff coverage is 96.77%.

❗ Current head 3869910 differs from pull request most recent head 825af89. Consider uploading reports for the commit 825af89 to get more accurate results

@@            Coverage Diff             @@
##           master     #388      +/-   ##
==========================================
- Coverage   61.97%   60.91%   -1.07%     
==========================================
  Files          71       71              
  Lines       10239     9934     -305     
==========================================
- Hits         6346     6051     -295     
+ Misses       2939     2929      -10     
  Partials      954      954              

Impacted Files	Coverage Δ
session/util.go	25.71% <0.00%> (+1.38%)	⬆️
netmap/types.go	32.64% <91.66%> (-7.65%)	⬇️
acl/types.go	31.74% <95.23%> (-9.08%)	⬇️
container/types.go	33.84% <97.91%> (-8.98%)	⬇️
session/types.go	31.78% <97.95%> (-9.24%)	⬇️
accounting/accounting.go	33.33% <100.00%> (-9.53%)	⬇️
audit/types.go	33.33% <100.00%> (-9.53%)	⬇️
object/types.go	36.58% <100.00%> (-8.92%)	⬇️
refs/types.go	47.25% <100.00%> (-6.60%)	⬇️
reputation/types.go	33.33% <100.00%> (-9.53%)	⬇️
... and 3 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 5016274...825af89. Read the comment docs.

[carpawell]

I would add issue number to the commit