refactor: require an explicit database username

src/connection.rs

@@ -85,12 +85,11 @@ struct Form {
 
 impl Default for Form {
     fn default() -> Self {
-        let user = std::env::var("USER").unwrap_or_default();
         Self {
             provider: 0,
             focus: 0,
             tls: 0,
-            postgres: ["localhost", "5432", "postgres", &user, ""].map(Input::from),
+            postgres: ["localhost", "5432", "postgres", "", ""].map(Input::from),
             path: Input::default(),
             error: None,
         }