build: drop man page stub that cannot be generated

[garlick]

Apparently we've asked asciidoc to generate one too many
man page stubs from flux_kvs_txn_create.adoc.

Since it's not generated, make install fails. For now,
drop the stub from the Makefile.am so make install can work.

Fixes #1256

[grondo]

Ok, that will work for now I guess. I guess we should open a longer term issue to deal with the missing manpage?

[codecov-io]

Codecov Report

Merging #1258 into master will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1258      +/-   ##
==========================================
- Coverage   77.89%   77.88%   -0.02%     
==========================================
  Files         154      154              
  Lines       28934    28934              
==========================================
- Hits        22537    22534       -3     
- Misses       6397     6400       +3

Impacted Files	Coverage Δ
src/broker/modservice.c	80.58% <0%> (-0.98%)	⬇️
src/common/libflux/response.c	83.73% <0%> (-0.82%)	⬇️
src/common/libkvs/kvs_txn.c	74.01% <0%> (-0.57%)	⬇️
src/broker/module.c	83.79% <0%> (-0.28%)	⬇️
src/common/libflux/handle.c	83.66% <0%> (-0.25%)	⬇️
src/common/libkvs/kvs.c	64.03% <0%> (ø)	⬆️
src/modules/kvs/kvs.c	62.62% <0%> (ø)	⬆️
src/common/libflux/message.c	81.6% <0%> (+0.11%)	⬆️
src/common/libutil/base64.c	95.77% <0%> (+0.7%)	⬆️

[coveralls]

Coverage increased (+0.007%) to 78.499% when pulling 5a36d08 on garlick:issue1256 into 2694116 on flux-framework:master.

[garlick]

Restarted one builder that failed here:

FAIL: t0001-basic.t 53 - instance can stop cleanly with subscribers (#1025)

that might be a new one but shouldn't be related to this PR.

[grondo]

Here's full output:

expecting success: 
	flux start ${ARGS} -s2 --bootstrap=selfpmi bash -c "nohup flux event sub hb &"

lt-flux-broker: module 'aggregator' was not cleanly shutdown
lt-flux-broker: module 'barrier' was not cleanly shutdown
lt-flux-broker: module 'kvs' was not cleanly shutdown
lt-flux-broker: module 'job' was not cleanly shutdown
lt-flux-broker: module 'resource-hwloc' was not cleanly shutdown
flux-event: flux_event_subscribe: Success
flux-start: 0 (pid 7531) Killed
not ok 53 - instance can stop cleanly with subscribers (#1025)

[garlick]

Thanks. I restarted another one that hung during setup.

[coveralls]

Coverage decreased (-0.01%) to 78.499% when pulling 2f5a3a8 on garlick:issue1256 into 1220202 on flux-framework:master.

[grondo]

Thanks!