configure: Drop --enable-githttp

Following Demi's work to use HTTPS everywhere, all users of GIT_HTTP have
been removed from the build system.  Drop the configure knob.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>

tools/configure.ac

@@ -84,7 +84,6 @@ AX_XEN_EXPAND_CONFIG()
 # Enable/disable options
 AX_ARG_DEFAULT_ENABLE([werror], [Build tools without -Werror])
 AX_ARG_DEFAULT_DISABLE([rpath], [Build tools with -Wl,-rpath,LIBDIR])
-AX_ARG_DEFAULT_DISABLE([githttp], [Download GIT repositories via HTTP])
 AX_ARG_DEFAULT_ENABLE([monitors], [Disable xenstat and xentop monitoring tools])
 AX_ARG_DEFAULT_ENABLE([ocamltools], [Disable Ocaml tools])
 AX_ARG_DEFAULT_ENABLE([xsmpolicy], [Disable XSM policy compilation])