Fix: forks to often when reading same KB in different scripts (#1654)

What:
Fix: forks to often when reading same KB in different scripts
Jira: SC-1090

Why:
It fork()s to much

How:
Set values in redis with set_kb_item. Then, read it from different scripts with get_kb_items()

openvas-nasl -X -d set_kb.nasl 1.nasl 2.nasl

nasl/nasl.c

@@ -386,13 +386,13 @@ main (int argc, char **argv)
 
           if (exec_nasl_script (script_infos, mode) < 0)
             err++;
+
+          if (process_id != getpid ())
+            exit (0);
         }
       g_free (script_infos->globals);
       g_free (script_infos);
 
-      if (process_id != getpid ())
-        exit (0);
-
       kb_delete (kb);
     }