Check for mal-formed lambda link.
Check for mal-formed lambda link.

Fixes issue #1496

AmeBel/atomspace,misgeatgit/atomspace,rTreutlein/atomspace,misgeatgit/atomspace,rTreutlein/atomspace,misgeatgit/atomspace,misgeatgit/atomspace,rTreutlein/atomspace,AmeBel/atomspace,AmeBel/atomspace,AmeBel/atomspace,misgeatgit/atomspace,rTreutlein/atomspace,rTreutlein/atomspace,AmeBel/atomspace