[Xotcl] NX: crash report

[Victor Mayevski]

The following (incorrect) usage will cause a crash:

*****
% o attribute {a v}
::o::a
% o::a       #Incorrect usage
Segmentation fault
*****

The next one, however, does not crash:

*****
% Object create o
::o
% o attribute {a v}
::o::a
% o a       # Correct usage first
v
% o::a      # Incorrect usage
can't read "o::a": no such variable
    while executing
"o::a"
%
*****