fixed some mistakes i introduced in activity.serializers after i removed fields.RootField"
fixed some mistakes i introduced in activity.serializers after i removed fields.RootField"

zimmerman-zimmerman/OIPA,zimmerman-zimmerman/OIPA,bryanph/OIPA,bryanph/OIPA,tokatikato/OIPA,openaid-IATI/OIPA,openaid-IATI/OIPA,openaid-IATI/OIPA,zimmerman-zimmerman/OIPA,openaid-IATI/OIPA,zimmerman-zimmerman/OIPA,tokatikato/OIPA,bryanph/OIPA,zimmerman-zimmerman/OIPA,tokatikato/OIPA,bryanph/OIPA,openaid-IATI/OIPA,tokatikato/OIPA