Add -Wno-unused-value

Makefile

@@ -1,5 +1,5 @@
 GIT_SHA=$(shell git rev-parse --short HEAD)
-DISABLED_WARNINGS=-Wno-switch -Wno-pointer-sign -Wno-tautological-constant-out-of-range-compare -Wno-tautological-compare -Wno-macro-redefined
+DISABLED_WARNINGS=-Wno-switch -Wno-pointer-sign -Wno-tautological-constant-out-of-range-compare -Wno-tautological-compare -Wno-macro-redefined -Wno-unused-value
 LDFLAGS=-pthread -ldl -lm -lstdc++
 CFLAGS=-std=c++14 -DGIT_SHA=\"$(GIT_SHA)\"
 CFLAGS:=$(CFLAGS) -DODIN_VERSION_RAW=\"dev-$(shell date +"%Y-%m")\"