comparaison between kernel completion and context-completin were
returning duplicate entry in some cases, due to trailing space.
sripping trailing space in comparaison prevent this.
fixes#3563
example
import bar
from foo im<tab>
used to propose `import` twice (actually `import` and `import[space]` as$
`import` was a token on the first line) now just complete directly to$
`import[space]`.
MinRK
Matthias BUSSONNIER
Brian E. Granger