Add GNU wget2 to oss-fuzz

[rockdaboot]

GNU Wget2 is the designated successor of GNU Wget. It comes with a libwget to provide wget functionality to other projects as well. It takes part in GSOC 2017 with 3 projects.

https://gitlab.com/gnuwget/wget2

[inferno-chromium]

LGTM, merging.

[inferno-chromium]

@rockdaboot - currently wget2 build is broken, can you please check why configure script is broken.
Step #3: + test -f config.h
Step #3: + ./configure --enable-static --disable-doc
Step #3: /src/build.sh: line 19: ./configure: No such file or directory
Finished Step #3
ERROR
ERROR: build step "gcr.io/oss-fuzz/wget2" failed: exit status 1

https://oss-fuzz-build-logs.storage.googleapis.com/index.html
https://oss-fuzz-build-logs.storage.googleapis.com/log-4383e13c-04b7-4ef3-8be8-8f65bc5634e7.txt

[rockdaboot]

#650 should fix it. How to enable automatic mail on build failures ?

[inferno-chromium]

We plan to implement notifications sometime in next month or so, but sorry it does not exist at the moment. Till then, we would appreciate if you can look at https://oss-fuzz-build-logs.storage.googleapis.com/index.html once in a week or otherwise would have to just wait on our pings :(