Multiline string in Python Console is not highlighted properly

* **Editor name and version**: Atom 1.27.1 & GitHub
* **Platform**: Ubuntu
* **Color scheme**: One Dark
* **MagicPython version**: 1.0.12
* **A sreenshot**:
* **5-10 lines of surrounding code**:
```pycon
>>> lua_func = lua.eval('''
... function(a, b) -- a plus b
... return a + b
... end
... ''')
```
* **The same code highlighted by Pygments**:

No source file or test is named. Reproduce the highlighting in Atom 1.27.1 on Ubuntu with MagicPython 1.0.12 using the supplied pycon snippet, then compare it with the Pygments screenshot; it is done when the multiline embedded Lua code is highlighted correctly.

Written by the indexing model from the issue text.