fix test for query generation

public/app/plugins/datasource/postgres/postgres_query.ts

@@ -17,7 +17,7 @@ export default class PostgresQuery {
     target.metricColumn = target.metricColumn || 'none';
 
     target.groupBy = target.groupBy || [];
-    target.where = target.where || [{ type: 'macro', params: ['$__timeFilter'] }];
+    target.where = target.where || [{ type: 'macro', name: '$__timeFilter', params: [] }];
     target.select = target.select || [[{ type: 'column', params: ['value'] }]];
 
     // handle pre query gui panels gracefully

public/app/plugins/datasource/postgres/specs/postgres_query.jest.ts

@@ -98,6 +98,7 @@ describe('PostgresQuery', function() {
       schema: 'public',
       table: 'table',
       select: [[{ type: 'column', params: ['value'] }]],
+      where: [],
     };
     let result = 'SELECT\n  t AS "time",\n  value\nFROM public.table\nORDER BY 1';
     let query = new PostgresQuery(target, templateSrv);