do not panic on loss of oneshot channel reciever

[bluejekyll]

fixes #355

[codecov]

Codecov Report

Merging #356 into master will increase coverage by 0.01%.
The diff coverage is 75%.

@@            Coverage Diff             @@
##           master     #356      +/-   ##
==========================================
+ Coverage   87.21%   87.23%   +0.01%     
==========================================
  Files         121      121              
  Lines       12359    12358       -1     
==========================================
+ Hits        10779    10780       +1     
+ Misses       1580     1578       -2

Impacted Files	Coverage Δ
proto/src/dns_handle.rs	83.49% <75%> (+0.88%)	⬆️

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