Raised field on crossing presets triggers geometry type warning

[1ec5]

As reported in OSMUS Slack, checking the Raised field on the line-based Pedestrian Crossing preset produces a warning about using traffic_calming=table on a line:

This regression of #733 seems to be related to #1076 (comment) and might require a fix in iD proper.

[democat3457]

Not sure if this also helps, but the warning shows up on crossings for all values of traffic_calming= except for:

• bump
• mini_bumps
• hump
• table
• cushion
• rumble_strip
• dip
• chicane
• choker
• island

Misspellings (and other invalid values) also produce the warning.