Ujaval Gandhi 899c57a91f Change comparison back to NULL
filter_null method previously filtered the NULL values using NULL type in qgis.core which is a QPyNullVariant. 
f9e0093ce7

This was subsequently changed to 'is not None' comparison which is incorrect. The current version fails to filter out the null values.
2016-01-04 11:01:06 +05:30
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2016-01-04 11:01:06 +05:30