Don't error on tohil namespace creation failure

There's a report from FlightAware hitting this error, but it's elusive,
happens only in the rivet apache module and not very often.

But the error can be caused simply by doing a

```tcl
    namespace eval ::tohil {}
    package require tohil
```

That ought to not be an error.  In fact, from high-level Tcl itself there's no
explicit way to cause a namespace-already-exists error because `namespace eval` creates the namespace
if it doesn't exist and is ok with it if it does.

The concern here is that there is some underlying problem with the
multiple tcl interpreter / python subinterpreter stuff.  But in any case
the above shouldn't be a traceback.

generic/tohil.c

@@ -4139,8 +4139,9 @@ Tohil_Init(Tcl_Interp *interp)
     if (Tcl_PkgProvide(interp, "tohil", PACKAGE_VERSION) != TCL_OK)
         return TCL_ERROR;
 
-    if (Tcl_CreateNamespace(interp, "::tohil", NULL, NULL) == NULL)
-        return TCL_ERROR;
+    //if (Tcl_CreateNamespace(interp, "::tohil", NULL, NULL) == NULL)
+    //    return TCL_ERROR;
+    Tcl_CreateNamespace(interp, "::tohil", NULL, NULL);
 
     // if i haven't been told python is up, tcl is the parent,
     // and we need to initialize the python interpreter and