[Version 4] with the default lint mode, "background", the linter is not run when a file is opened
Using ST 3 dev build 3157, SublimeLinter 4.0.1, SublimeLinter-eslint 4.0.0, ESlint 4.18.1 in win10x64

I quote from the SublimeLinter.sublime-settings:

```javascript
    // Lint Modes determine when the linter is run
    // background: asynchronously on every change
    // load_save: when a file is opened and every time it's saved
    // manual: only when calling the Lint This View command
    "lint_mode": "background",
```

i.e. i. SL4 with the default lint mode, "background", whenever you open a file, the linter is not run. It's only run if you modify the file, i.e. type or delete something on it.
But, if you don't want or just forget to modify it, then it's not linted, giving you the wrong impression that the file is fine.

_For reference, in SL3, with the "background" lint mode, the file was linted on load._

What I'd prefer is having a 4th mode, something like" load_and_background",
i.e. lint the file on load, and then lint it again asynchronously on every change.

<br/>

So, could you please consider adding such a lint mode? That's my suggestion.
diff --git a/sublime_linter.py b/sublime_linter.py
index 220a3ab..404685c 100644
--- a/sublime_linter.py
+++ b/sublime_linter.py
@@ -162,7 +162,7 @@ def has_syntax_changed(view):
     try:
         old_value = buffer_syntaxes[bid]
     except KeyError:
-        return False
+        return True
     else:
         return old_value != current_syntax
     finally:
['sublime_linter.py']