Revert "allow yesod-form-1.7 (closes #5983)"
Revert "allow yesod-form-1.7 (closes #5983)"

This reverts commit f0401cfd9b5ea6066d96b743b0e8ed07b990d8f3.

Stackage isn't seeing the hledger-web revision yet
Maybe because the nightly script was not running?

simonmichael/stackage,iand675/stackage,Daniel-Diaz/stackage,jonschoning/stackage,mrkkrp/stackage