exporter: add field alias for count(*) func

If not adding an alias for count(*), the Count field of
projectCount will always be 0, because it can't be parsed from the correct field name.

Signed-off-by: bin liu <liubin0329@gmail.com>

src/pkg/exporter/project_collector.go

@@ -28,7 +28,7 @@ import (
 const ProjectCollectorName = "ProjectCollector"
 
 var (
-	totalProjectSQL = `SELECT project_metadata.value AS public, COUNT(project_metadata.value)
+	totalProjectSQL = `SELECT project_metadata.value AS public, COUNT(project_metadata.value) as count
 	FROM project INNER JOIN project_metadata ON project.project_id=project_metadata.project_id
 	WHERE project.deleted=FALSE AND project_metadata.name='public'
 	GROUP BY project_metadata.value;`