THRIFT-4515: cross server test improvement: graceful test server shutdown

This closes #1509
diff --git a/configure.ac b/configure.ac
index 9efc28b..917f6fa 100755
--- a/configure.ac
+++ b/configure.ac
@@ -633,6 +633,7 @@
 AC_CHECK_HEADERS([netdb.h])
 AC_CHECK_HEADERS([netinet/in.h])
 AC_CHECK_HEADERS([pthread.h])
+AC_CHECK_HEADERS([signal.h])
 AC_CHECK_HEADERS([stddef.h])
 AC_CHECK_HEADERS([stdlib.h])
 AC_CHECK_HEADERS([sys/ioctl.h])