Remove duplicate block for part_of_speech on Glossary entries.

[garrett-eclipse]

Hello,

I was hoping we could revert an unintentional block in GlotPress, code to cleanup is in this PR;
​https://github.com/GlotPress/GlotPress-WP/pull/947#issuecomment-429450441

This block currently doesn't allow users to create two nouns for the same term which for romance languages is required.

This is holding back a Make/Polyglots post found here;
​https://github.com/Mte90/GlotDict/wiki/Glossary-Entries-should-be-1-to-1-(%60_doing_it_wrong%60)

Implementing this will allow all the locales mentioned to correct their Glossaries for better term flagging and warnings.

Greatly appreciated.

[garrett-eclipse]

Blocking error which doesn't allow multiple nouns for a term

[ocean90]

There's no need for a separate issue. GlotPress gets updated from time to time.