dataset_analyser: replace tomo_n with len(projections)

nabu/resources/dataset_analyzer.py

@@ -91,7 +91,7 @@ class DatasetAnalyzer(object):
         self.projections = self.dataset_scanner.projections
         self.flats = self.dataset_scanner.flats
         self.darks = self.dataset_scanner.darks
-        self.n_angles = self.dataset_scanner.tomo_n
+        self.n_angles = len(self.dataset_scanner.projections)
         self.radio_dims = (self.dataset_scanner.dim_1, self.dataset_scanner.dim_2)
         self._binning = (1, 1)
         self.translations = None