Revert "Issue #3007424 by acbramley, Spokje, mbovan, narendra.rajwar27,...

Revert "Issue #3007424 by acbramley, Spokje, mbovan, narendra.rajwar27, AaronBauman, ravi.shankar, aleevas, geek-merlin, jibran, YurkinPark, daffie, larowlan, alexpott, marcelovani, catch, Berdir, Lendude, mstrelan, tar_inet, andrewbelcher, seanB, Honza Pobořil, danflanagan8, susgo, yogeshmpawar, sylus, sjpeters79, raman.b: Multiple usages of FieldPluginBase::getEntity do not check for NULL, leading to WSOD"

This reverts commit 7ea52649.