fix MulticastProcessor javadoc comment

[satoshun]

fix wrong javadoc comment of MulticastProcessor.
I think #create(boolean) is an optional refcount behavior.

[codecov]

Codecov Report

Merging #6042 into 2.x will increase coverage by 0.07%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##                2.x   #6042      +/-   ##
===========================================
+ Coverage     98.23%   98.3%   +0.07%     
- Complexity     6168    6172       +4     
===========================================
  Files           665     665              
  Lines         44730   44730              
  Branches       6205    6205              
===========================================
+ Hits          43942   43974      +32     
+ Misses          241     223      -18     
+ Partials        547     533      -14

Impacted Files	Coverage Δ	Complexity Δ
...va/io/reactivex/processors/MulticastProcessor.java	98.67% <ø> (ø)	84 <0> (ø)	⬇️
...ternal/operators/observable/ObservablePublish.java	96.46% <0%> (-3.54%)	11% <0%> (ø)
...nternal/operators/parallel/ParallelSortedJoin.java	92.7% <0%> (-2.19%)	2% <0%> (ø)
...java/io/reactivex/processors/PublishProcessor.java	98.19% <0%> (-1.81%)	42% <0%> (-1%)
...rnal/operators/flowable/FlowableFlatMapSingle.java	92.93% <0%> (-1.64%)	2% <0%> (ø)
...io/reactivex/subscribers/SerializedSubscriber.java	98.86% <0%> (-1.14%)	26% <0%> (-1%)
...perators/observable/ObservableMergeWithSingle.java	99.06% <0%> (-0.94%)	2% <0%> (ø)
...ernal/operators/flowable/FlowableTimeoutTimed.java	98.37% <0%> (-0.82%)	3% <0%> (ø)
...x/internal/operators/observable/ObservableZip.java	99.29% <0%> (-0.71%)	6% <0%> (ø)
...x/internal/operators/flowable/FlowableFlatMap.java	89.47% <0%> (-0.27%)	4% <0%> (ø)
... and 22 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 5d8b0ac...045de57. Read the comment docs.