Upgrade DUB build target to use $DMD instead of $DC

Author: wilzbach

posix.mak

@@ -560,7 +560,7 @@ ${STABLE_DMD}:
 		unzip -qd ${STABLE_DMD_ROOT} $${TMPFILE}.zip && rm $${TMPFILE}.zip
 
 ${DUB}: ${DUB_DIR} ${STABLE_DMD}
-	cd ${DUB_DIR} && DC="$(abspath ${STABLE_DMD}) -conf=$(abspath ${STABLE_DMD_CONF})" ./build.sh
+	cd ${DUB_DIR} && DMD="${STABLE_DMD}" ./build.sh
 
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