p2p: Avoid InitError when downgrading peers.dat

fixes #24188
When downgrading, a peers.dat with a future version that has a minimum
required version larger than the downgraded version would cause an InitError.

This commit changes this behavior to overwrite the existing peers.dat with
a new empty one, while creating a backup in peers.dat.bak.

1 files changed, 6 insertions, 0 deletions

diff --git a/src/addrman.h b/src/addrman.h
index 0646ef368d..472282833b 100644
--- a/src/addrman.h
+++ b/src/addrman.h
@@ -17,6 +17,12 @@
 #include <utility>
 #include <vector>
 
+class InvalidAddrManVersionError : public std::ios_base::failure
+{
+public:
+    InvalidAddrManVersionError(std::string msg) : std::ios_base::failure(msg) { }
+};
+
 class AddrManImpl;
 
 /** Default for -checkaddrman */