Merge #12447: test: Add missing signal.h header

dd7e42c test: Add missing signal.h header (Wladimir J. van der Laan)

Pull request description:

  util_tests.cpp needs to include the signal.h header on FreeBSD.

  Reported by denis2342 on IRC.

Tree-SHA512: 0b946fc2770ca6043087f4fe22be96848d46efe44e3d4d45c5ee663e0f95b0e2e6145f4ade577a6257d0c0c4cfadf324111799e78b9e4e4be4da8a90f68e349f

Author: MarcoFalke

src/test/util_tests.cpp

@@ -14,6 +14,7 @@
 #include <stdint.h>
 #include <vector>
 #ifndef WIN32
+#include <signal.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #endif