Replaced all usage of catalog with schema.

Catalog was used by mistake.
Spring Data JDBC has no support for multiple catalogs, only for multiple schema.

Closes #1729

Author: schauder

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/mapping/schema/LiquibaseChangeSetWriter.java

@@ -337,7 +337,7 @@ private SchemaDiff differenceOf(Database database) throws LiquibaseException {
 		Tables existingTables = getLiquibaseModel(database);
 		Stream<? extends RelationalPersistentEntity<?>> entities = mappingContext.getPersistentEntities().stream()
 				.filter(schemaFilter);
-		Tables mappedEntities = Tables.from(entities, sqlTypeMapping, database.getDefaultCatalogName(), mappingContext);
+		Tables mappedEntities = Tables.from(entities, sqlTypeMapping, database.getDefaultSchemaName(), mappingContext);
 
 		return SchemaDiff.diff(mappedEntities, existingTables, nameComparator);
 	}
@@ -463,7 +463,7 @@ private Tables getLiquibaseModel(Database targetDatabase) throws LiquibaseExcept
 				continue;
 			}
 
-			Table tableModel = new Table(table.getSchema().getCatalogName(), table.getName());
+			Table tableModel = new Table(table.getSchema().getName(), table.getName());
 
 			List<liquibase.structure.core.Column> columns = table.getColumns();