I checked this, the function as "added around Aug 11, 2005" and my AMX Mod X 1.60 was compiled at September 2005 ...
Checking "strings" on the dll, shows the following:
grep query_client_cvar strings_amxmodx_mm_i386.so
query_client_cvar
So, it is contained!
So, i will probably just need a newer MetaMod ...
Will write back
Edit: It seems, the "Metamod-P" version will be need, or does the "regular" version from
www.metamod.org also contain the needed changes?!?