fix: add $(PTHREAD_FLAGS) to dash_util_LDFLAGS

Author: kwvg

src/Makefile.am

@@ -1130,7 +1130,7 @@ endif
 dash_util_SOURCES = bitcoin-util.cpp
 dash_util_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 dash_util_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
-dash_util_LDFLAGS = $(LDFLAGS_WRAP_EXCEPTIONS) $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
+dash_util_LDFLAGS = $(LDFLAGS_WRAP_EXCEPTIONS) $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS) $(PTHREAD_FLAGS)
 
 if TARGET_WINDOWS
 dash_util_SOURCES += bitcoin-util-res.rc