Rename column 'value' to 'value_'

In sql 'value' is a reserved word and should not be used (unless
quoted). Postgresql and MariaDB are ok with it, but the new version of
h2 is now complaining.

modules/store/src/main/scala/docspell/store/records/RContact.scala

@@ -30,7 +30,7 @@ object RContact {
     val tableName = "contact"
 
     val contactId = Column[Ident]("contactid", this)
-    val value = Column[String]("value", this)
+    val value = Column[String]("value_", this)
     val kind = Column[ContactKind]("kind", this)
     val personId = Column[Ident]("pid", this)
     val orgId = Column[Ident]("oid", this)