correct description in binning dialog

src/gui_qt/math/binning.py

@@ -7,7 +7,7 @@ class BinningWindow(QtWidgets.QDialog):
 
         layout = QtWidgets.QFormLayout()
 
-        self.label = QtWidgets.QLabel('Digits (negative values position left of decimal point)')
+        self.label = QtWidgets.QLabel('Bin width')
         self.spinbox = QtWidgets.QLineEdit()
         self.spinbox.setValidator(QtGui.QDoubleValidator())
         self.spinbox.setText('1')