Fix a missed getData() call in JX.Request
Fix a missed getData() call in JX.Request

Summary:
Missed this in the list-of-pairs conversion.

Test Plan:
File uploads work.

Reviewed By: aran
Reviewers: tomo, aran
CC: aran
Differential Revision: 331

phacility/javelin,phacility/javelin,phacility/javelin,phacility/javelin,phacility/javelin