build: fix mingw build

./autobuild.sh died on several messages resembling:

../../src/rpc/virnetsocket.c: In function 'virNetSocketNewListenTCP':
../../src/rpc/virnetsocket.c:231:9: error: implicit declaration of function 'bind_used_without_requesting_gnulib_module_bind' [-Wimplicit-function-declaration]
../../src/rpc/virnetsocket.c:231:9: error: nested extern declaration of 'bind_used_without_requesting_gnulib_module_bind' [-Wnested-externs]

Basically, gnulib socket fds are not safe to pass to mingw socket
functions unless we pull in those gnulib modules.

* bootstrap.conf (gnulib_modules): Add modules to handle socket
functions on mingw.

bootstrap.conf

@@ -19,8 +19,10 @@
 
 # gnulib modules used by this package.
 gnulib_modules='
+accept
 areadlink
 base64
+bind
 byteswap
 c-ctype
 c-strcase
@@ -40,6 +42,8 @@ getaddrinfo
 getcwd-lgpl
 gethostname
 getpass
+getpeername
+getsockname
 gettext-h
 gettimeofday
 gitlog-to-changelog
@@ -48,6 +52,7 @@ ignore-value
 inet_pton
 intprops
 ioctl
+listen
 maintainer-makefile
 manywarnings
 mkstemp