Revert "Set content-type to routes that had none set"
Revert "Set content-type to routes that had none set"

This reverts commit 0dc67226dd38d5e603c9abc9f443809010ae85ee.

No longer needed after 944cd04.

Resolves: openbmc/openbmc#1932

Change-Id: I0f0a3fe2462cfd287ea7d7692fa47de685d595ea
Signed-off-by: Brad Bishop <713d098c0be4c8fd2bf36a94cd08699466677ecd@fuzziesquirrel.com>

openbmc/phosphor-rest-server,openbmc/phosphor-rest-server