config.c adjust config limits and mutable

- make lua-replicate-commands mutable (it never was, but i don't see why)
- make tcp-backlog immutable (fix a recent refactory mistake)
- increase the max limit of a few configs to match what they were before
the recent refactory

tests/unit/introspection.tcl

@@ -65,7 +65,7 @@ start_server {tags {"introspection"}} {
             rdbchecksum
             daemonize
             io-threads-do-reads
-            lua-replicate-commands
+            tcp-backlog
             always-show-logo
             syslog-enabled
             cluster-enabled