bootstrap.conf: drop c-strcasestr gnulib module

Last usage was removed by commit
<41f88886> and commit
<0f4d3172> forgot to drop include.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NFabiano Fidêncio <fidencio@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

bootstrap.conf

@@ -22,7 +22,6 @@ accept
 bind
 c-ctype
 c-strcase
-c-strcasestr
 canonicalize-lgpl
 chown
 clock-time

src/qemu/qemu_monitor_json.c

@@ -40,7 +40,6 @@
 #include "virprobe.h"
 #include "virstring.h"
 #include "cpu/cpu_x86.h"
-#include "c-strcasestr.h"
 #include "virenum.h"
 
 #ifdef WITH_DTRACE_PROBES