clang: Add missing defines.

.clang_complete

@@ -1 +1,11 @@
--Iinclude -Ibuild -Itests -Isrc
+-DWITH_SERVER=1
+-DWITH_GSSAPI=1
+-DWITH_ZLIB=1
+-DWITH_SFTP=1
+-DWITH_SSH1=1
+-DWITH_PCAP=1
+-Iinclude/libssh
+-Iinclude
+-Ibuild
+-Itests
+-Isrc