Make ClientInterface::statenames consistent with the state enum again

Fixes minetest.get_player_information segfault due
to out of bounds access problems, when compiled as debug build.

src/clientiface.h

@@ -167,6 +167,9 @@ namespace con {
 
 #define CI_ARRAYSIZE(a) (sizeof(a) / sizeof((a)[0]))
 
+// Also make sure to update the ClientInterface::statenames
+// array when modifying these enums
+
 enum ClientState
 {
 	CS_Invalid,