Backoffice doesn't work for postgres with fields of type char

[FroMage]

Apparently, postgres disallows char fields with a 0 (default) value, resulting in interesting issues like:

	Suppressed: org.hibernate.exception.DataException: could not execute statement [ERROR: invalid byte sequence for encoding "UTF8": 0x00
  Where: unnamed portal parameter $19] [insert into ExampleEntity (arrayBlob,date,enumeration,lobString,localDate,localDateTime,somethingLocalTime,longString1,longString2,longString3,longString4,manyToOne_id,contents,mimeType,name,oneToOneOwning_id,primitiveBoolean,primitiveByte,primitiveChar,primitiveDouble,primitiveFloat,primitiveInt,primitiveLong,primitiveShort,requiredString,sqlBlob,string,wrapperBoolean,wrapperInt,id) values (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)]

Not sure what value to attach to a char under those circumstances.