Add unset (incorrectly removed)

Author: oech3

GNUmakefile

@@ -401,7 +401,7 @@ distclean: clean
 ifeq ($(MANPAGES),y)
 # Do not cross-build uudoc
 build-uudoc:
-	${CARGO} build ${CARGOFLAGS} --bin uudoc --features "uudoc ${EXES}" ${PROFILE_CMD} --no-default-features
+	@unset CARGO_BUILD_TARGET && ${CARGO} build ${CARGOFLAGS} --bin uudoc --features "uudoc ${EXES}" ${PROFILE_CMD} --no-default-features
 
 install-manpages: build-uudoc
 	mkdir -p $(DESTDIR)$(DATAROOTDIR)/man/man1