Use another augmented assignment statement

[elfring]

👀 Some source code analysis tools can help to find opportunities for improving software components.
💭 I propose to increase the usage of augmented assignment statements accordingly.

diff --git a/python_speech_features/sigproc.py b/python_speech_features/sigproc.py
index a786c4f..b8729ea 100644
--- a/python_speech_features/sigproc.py
+++ b/python_speech_features/sigproc.py
@@ -84,7 +84,7 @@ def deframesig(frames, siglen, frame_len, frame_step, winfunc=lambda x: numpy.on
                                                indices[i, :]] + win + 1e-15  # add a little bit so it is never zero
         rec_signal[indices[i, :]] = rec_signal[indices[i, :]] + frames[i, :]
 
-    rec_signal = rec_signal / window_correction
+    rec_signal /= window_correction
     return rec_signal[0:siglen]