Log variables moved to log_manager.h

The log manager variables lm_enabled_log_files_bitmask, log_ses_count
and tls_log_info that earlier were declared separately in every
c-file are now declared in the log_manager.h header.

log_manager/log_manager.h

@@ -136,6 +136,10 @@ enum log_flush
 
 EXTERN_C_BLOCK_BEGIN
 
+extern int lm_enabled_logfiles_bitmask;
+extern ssize_t log_ses_count[];
+extern __thread log_info_t tls_log_info;
+
 bool skygw_logmanager_init(int argc, char* argv[]);
 void skygw_logmanager_done(void);
 void skygw_logmanager_exit(void);