Adding explicit libraries for CentOS builds.

Makefile.in

@@ -6,7 +6,7 @@ CPPFLAGS=@CPPFLAGS@ @OPENSSL_INCLUDES@
 DEFS=@DEFS@
 COMPILE_FLAGS=${CFLAGS} ${CPFLAGS} ${CPPFLAGS} ${DEFS} -Wall -Werror -Wextra -Wno-missing-field-initializers -Wno-deprecated-declarations -fno-strict-aliasing -fno-omit-frame-pointer -ggdb -Wno-unused-parameter -fPIC
 EXTRA_LIBS=@LIBS@ @EXTRA_LIBS@ @OPENSSL_LIBS@
-LOCAL_LDFLAGS=-rdynamic -ggdb -levent ${EXTRA_LIBS}
+LOCAL_LDFLAGS=-rdynamic -ggdb -levent ${EXTRA_LIBS} -ldl -lpthread -lutil
 LINK_FLAGS=${LDFLAGS} ${LOCAL_LDFLAGS}
 
 DEP=dep