[FIX] Solve annotation issue (#696)

* Always redefining the annotation.

* [EHN] fixing

---------

Signed-off-by: Bru <a.bruno@aluno.ufabc.edu.br>

Author: bruAristimunha

docs/source/whats_new.rst

@@ -32,7 +32,8 @@ Bugs
 - Improving the CI (:gh:`686` by `Bruno Aristimunha`_)
 - Making the download test work again (:gh:`693` by `Bruno Aristimunha`_)
 - Fix the EpochSelectChannel that caused incorrect channel selection in `example <examples/plot_Hinss2021_classification.py>` (:gh:`685` by `AFF`)
-- Fixing the logger on the Stieger2021 and Wang2016 dataset (:gh:`693` by `Bruno Aristimunha`_)
+- Fixing the logger on the Stieger2021 and Wang2016 dataset (:gh:`693` by `Bruno Aristimunha`_
+- Fixing bug with braindecode and moabb datasets EPFLP300 (:gh:`696` by `Bruno Aristimunha`_)
 - Change the way of creating the path to the folder (by `Sebastien Velut`_)
 
 API changes

moabb/datasets/preprocessing.py

@@ -66,8 +66,7 @@ def __init__(self, event_id, interval: Tuple[float, float]):
     def transform(self, raw, y=None):
         duration = self.interval[1] - self.interval[0]
         offset = int(self.interval[0] * raw.info["sfreq"])
-        if raw.annotations:
-            return raw
+
         stim_channels = mne.utils._get_stim_channel(None, raw.info, raise_error=False)
         if len(stim_channels) == 0:
             log.warning(