Bump plugin interface version

Author: apaillier-ledger

src/eth_plugin_interface.h

@@ -12,7 +12,8 @@ typedef enum {
     ETH_PLUGIN_INTERFACE_VERSION_1 = 1,
     ETH_PLUGIN_INTERFACE_VERSION_2 = 2,
     ETH_PLUGIN_INTERFACE_VERSION_3 = 3,
-    ETH_PLUGIN_INTERFACE_VERSION_LATEST = 4,
+    ETH_PLUGIN_INTERFACE_VERSION_4 = 4,
+    ETH_PLUGIN_INTERFACE_VERSION_LATEST = 5,
 } eth_plugin_interface_version_t;
 
 typedef enum {