bpf: remove HOST_REDIRECT_TO_INGRESS from LXC_OPTIONS in Makefile

Commit 3b64f23 ("Deprecate legacy flannel integration") removed all
traces of HOST_REDIRECT_TO_INGRESS, but commit 652ccd2
("lib/proxy.h: set variable as maybe unused to avoid compilation error")
accidentially added it to LXC_OPTIONS again.

Signed-off-by: Tobias Klauser <tobias@cilium.io>

bpf/Makefile

@@ -220,7 +220,6 @@ bpf_xdp.o: bpf_xdp.ll
 
 # The following option combinations are compile tested
 LXC_OPTIONS = \
-	 -DHOST_REDIRECT_TO_INGRESS: \
 	 -DALLOW_ICMP_FRAG_NEEDED: \
 	 -DSKIP_DEBUG: \
 	 -DHAVE_LPM_TRIE_MAP_TYPE: \