Update all sourceware links to https. The website redirects
everything to https anyway so let the web server do a bit less work.
The only reference that remains unchanged is the one in the old
ChangeLog, since it didn't seem worth changing it.
* NEWS: Update sourceware link to https.
* configure.ac: Likewise.
* crypt/md5test-giant.c: Likewise.
* dlfcn/bug-atexit1.c: Likewise.
* dlfcn/bug-atexit2.c: Likewise.
* localedata/README: Likewise.
* malloc/tst-mallocfork.c: Likewise.
* manual/install.texi: Likewise.
* nptl/tst-pthread-getattr.c: Likewise.
* stdio-common/tst-fgets.c: Likewise.
* stdio-common/tst-fwrite.c: Likewise.
* sunrpc/Makefile: Likewise.
* sysdeps/arm/armv7/multiarch/memcpy_impl.S: Likewise.
* wcsmbs/tst-mbrtowc2.c: Likewise.
* configure: Regenerate.
* INSTALL: Regenerate.
* malloc/arena.c (ptmalloc_lock_all): If global lock already taken
by the same thread, just bump the counter.
(ptmalloc_unlock_all): If counter for recursive locks hasn't reached
zero, don't do anything else.
* malloc/Makefile (tests): Add tst-mallocfork.
* malloc/tst-mallocfork.c: New file.
