Fix unintended bit overwriting with sparse bit offsets.

Any bit for which the replacement pattern contained a 1 bit in one of
the "holes", would be set despite not being part of the desired mask.

Author: acolomb

canopen/objectdictionary/__init__.py

@@ -553,7 +553,7 @@ def encode_bits(
         for bit in bits:
             mask |= 1 << bit
         temp &= ~mask
-        temp |= bit_value << min(bits)
+        temp |= (bit_value << min(bits)) & mask
         return temp