Merge branch 'bugfix/encrypted_partition_flag' into 'master'

Use PART_FLAG_ENCRYPTED value in gen_esp32part.py

Currently paritions marked as encrypted by gen_esp32part.py are not
recognized as such and encrypted writes don't work.

This is part of espressif/esp-idf#253

Merges Pull Request #293 https://github.com/espressif/esp-idf/pull/293

See merge request !470

components/partition_table/gen_esp32part.py

@@ -144,7 +144,7 @@ class PartitionDefinition(object):
     # dictionary maps flag name (as used in CSV flags list, property name)
     # to bit set in flags words in binary format
     FLAGS = {
-        "encrypted" : 1
+        "encrypted" : 0
     }
 
     # add subtypes for the 16 OTA slot values ("ota_XXX, etc.")