make: CFLAGS cleanup

Readability, and don't -I embedded lmdb if not using it.

config.mk

@@ -31,7 +31,9 @@ INSTALL := install
 
 # Flags
 BUILD_LDFLAGS += $(LDFLAGS)
-BUILD_CFLAGS := $(CFLAGS) -std=c99 -D_GNU_SOURCE -Wno-unused -Wtype-limits -Wformat -Wformat-security -Wall -I$(abspath .) -I$(abspath lib/generic) -I$(abspath contrib) -I$(abspath contrib/lmdb)
+BUILD_CFLAGS := $(CFLAGS) -std=c99 -D_GNU_SOURCE
+BUILD_CFLAGS += -Wno-unused -Wtype-limits -Wformat -Wformat-security -Wall
+BUILD_CFLAGS += -I$(abspath .) -I$(abspath lib/generic) -I$(abspath contrib)
 BUILD_CFLAGS += -DPACKAGE_VERSION="\"$(VERSION)\"" -DPREFIX="\"$(PREFIX)\"" -DMODULEDIR="\"$(MODULEDIR)\""
 BUILD_CFLAGS += -fvisibility=hidden
 ifeq (,$(findstring -O,$(CFLAGS)))

contrib/contrib.mk

@@ -16,6 +16,7 @@ contrib_SOURCES += contrib/lmdb/mdb.c \
                    contrib/lmdb/midl.c
 contrib_CFLAGS  += -pthread
 contrib_LIBS    += -pthread
+lmdb_CFLAGS     += -I$(abspath contrib/lmdb)
 endif
 
 $(eval $(call make_static,contrib,contrib))