Perf test escaping sometimes fails

[333fred]

The string escaping in perf tests sometimes fails, resulting in broken builds that shouldn't have failed. Some examples include:

• https://ci.dot.net/job/dotnet_roslyn/job/master/job/windows_release_unit64_prtest/1080/console
• https://ci.dot.net/job/dotnet_roslyn/job/master/job/windows_debug_unit32_prtest/4807/console

[333fred]

This is because the Pull Title isn't properly escaped here: https://github.com/dotnet/roslyn/blob/master/cibuild.cmd#L98

[333fred]

The root cause is coming from here: https://github.com/jenkinsci/ghprb-plugin/blob/master/src/main/java/org/jenkinsci/plugins/ghprb/GhprbTrigger.java#L360. The pull title needs to be escaped.

[333fred]

@mmitche @TyOverby @jaredpar I've submitted jenkinsci/ghprb-plugin#430 to ghprb.