Merge pull request #1690 from OffchainLabs/config_doc_fix

change block-age config documentation

arbnode/execution/blockchain.go

@@ -40,7 +40,7 @@ type CachingConfig struct {
 func CachingConfigAddOptions(prefix string, f *flag.FlagSet) {
 	f.Bool(prefix+".archive", DefaultCachingConfig.Archive, "retain past block state")
 	f.Uint64(prefix+".block-count", DefaultCachingConfig.BlockCount, "minimum number of recent blocks to keep in memory")
-	f.Duration(prefix+".block-age", DefaultCachingConfig.BlockAge, "minimum age a block must be to be pruned")
+	f.Duration(prefix+".block-age", DefaultCachingConfig.BlockAge, "minimum age of recent blocks to keep in memory")
 	f.Duration(prefix+".trie-time-limit", DefaultCachingConfig.TrieTimeLimit, "maximum block processing time before trie is written to hard-disk")
 	f.Int(prefix+".trie-dirty-cache", DefaultCachingConfig.TrieDirtyCache, "amount of memory in megabytes to cache state diffs against disk with (larger cache lowers database growth)")
 	f.Int(prefix+".trie-clean-cache", DefaultCachingConfig.TrieCleanCache, "amount of memory in megabytes to cache unchanged state trie nodes with")