Please exercise your commit rights responsibly

[Stephan Bergmann]

Out of courtesy towards your fellow developers:

When Jenkins indicates multiple times in a row that a specific Gerrit 
change hangs the build:  Please do not override Jenkins -1 and submit 
the change anyway.  Please do not assume that others are happy about the 
consequences, and please do not assume that others are eager to fix the 
ensuing mess.

Please always test your changes locally with `make check` before sending 
them to Gerrit.  Or at least, once Jenkins makes it obvious that there 
is a certain failure pattern with a Gerrit change of yours, try to 
understand and solve whatever issue there is.

We inevitably all make mistakes all the time, and that is OK.  Just try 
to make good use of the safety measures that are available.