fix some bugs

- use writeConnect all the time unless filling old entries
- update column names to clarify UTC datetime
- GORM omit Mission association for server events that won't have one
- add disconnectDB function to reinit while active

extension/go.mod

@@ -4,6 +4,6 @@ go 1.16
 
 require (
 	github.com/go-sql-driver/mysql v1.7.0
-	gorm.io/driver/mysql v1.5.1 // indirect
-	gorm.io/gorm v1.25.2 // indirect
+	gorm.io/driver/mysql v1.5.1
+	gorm.io/gorm v1.25.2
 )