crashfix: SendUserEmailOnFieldUpdate crashes on users without an email

Created by: efritz

log15.Log methods have the signature that expects a message, key, value, key, value, .... Here, we're passing ctx where it expects a string, which causes the log line to crash the current goroutine.

This was preventing all e2e tests from running.

Fixes https://github.com/sourcegraph/sourcegraph/issues/14649

Created by: codecov[bot]

Codecov Report

Merging #14648 into main will increase coverage by 0.00%. The diff coverage is 0.00%.

@@           Coverage Diff           @@
##             main   #14648   +/-   ##
=======================================
  Coverage   52.24%   52.24%           
=======================================
  Files        1555     1555           
  Lines       79128    79128           
  Branches     6960     6960           
=======================================
+ Hits        41340    41342    +2     
+ Misses      34056    34055    -1     
+ Partials     3732     3731    -1     

Flag	Coverage Δ		*Carryforward flag
#go	52.57% <0.00%> (+<0.01%)
#integration	30.79% <ø> (ø)		Carriedforward from 4638b5c
#storybook	22.01% <ø> (ø)		Carriedforward from 4638b5c
#typescript	51.44% <ø> (ø)		Carriedforward from 4638b5c
#unit	33.22% <ø> (ø)		Carriedforward from 4638b5c

*This pull request uses carry forward flags. Click here to find out more.

Impacted Files	Coverage Δ
cmd/frontend/backend/user_emails.go	54.34% <0.00%> (ø)
internal/db/helpers.go	100.00% <0.00%> (ø)
internal/gosrc/stdlib.go	100.00% <0.00%> (ø)
internal/conf/platform.go	100.00% <0.00%> (ø)
internal/routevar/util.go	100.00% <0.00%> (ø)
internal/timeutil/week.go	100.00% <0.00%> (ø)
internal/vcs/git/mocks.go	100.00% <0.00%> (ø)
internal/db/query/query.go	100.00% <0.00%> (ø)
internal/highlight/mocks.go	100.00% <0.00%> (ø)
internal/routevar/regexp.go	100.00% <0.00%> (ø)
... and 765 more