Fix pickleio changing the reduce for spiketrain and irregularlysamplesignal

Author: samuelgarcia

neo/core/irregularlysampledsignal.py

@@ -237,7 +237,7 @@ def __reduce__(self):
             self.units,
             self.times.units,
             self.dtype,
-            True,
+            None,
             self.name,
             self.file_origin,
             self.description,

neo/core/spiketrain.py

@@ -497,7 +497,7 @@ def __reduce__(self):
             self.t_stop,
             self.units,
             self.dtype,
-            True,
+            None,
             self.sampling_rate,
             self.t_start,
             self.waveforms,