Revert incorrect change in ambiguity resolution

[Ladicek]

We previously [1] changed wording in the ambiguity resolution specification from

Return an Iterator, that iterates over the set of contextual references
for the resulting beans and required type, as defined in <<contextual_reference>>.

to

Return an Iterator, that iterates over the set of contextual references
for the resulting beans, as defined in <<contextual_reference>>.

This was an attempt to simplify the text, but is in fact incorrect, because a contextual reference is always determined by the bean and the bean type.

This commit reverts to the previous wording.

[1] 74827d2

[manovotn]

Good catch, I do recall we had that discussion about contextual references but I didn't recall we did this change earlier.