addrman: Log too low compat value

Also remove uint8_t{} casts from values that are already of the same
type.

test/sanitizer_suppressions/ubsan

@@ -62,7 +62,6 @@ implicit-integer-sign-change:script/bitcoinconsensus.cpp
 implicit-integer-sign-change:script/interpreter.cpp
 implicit-integer-sign-change:serialize.h
 implicit-integer-sign-change:txmempool.cpp
-implicit-signed-integer-truncation:addrman.cpp
 implicit-signed-integer-truncation:crypto/
 implicit-unsigned-integer-truncation:crypto/
 shift-base:arith_uint256.cpp