i have tried below steps to upgrade using ssh

(USB connection) ssh nemo@192.168.2.15
(WIFI) ssh nemo@192.168.0.7 (just check out your ip address in developer tab in wifi section)

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// Updating process...

1. ssu dr adaptation-community

2. ssu lr # Opt: Verify that 'adaptiation-community' is disabled

3. ssu ar adaptation-community-hammerhead http://repo.merproject.org/obs/home:/mautz/sailfishos_update_version/
e.g : ssu ar adaptation-community-hammerhead http://repo.merproject.org/obs/home:/mautz/sailfishos_2.2.0.29/

4. ssu lr # OPTIONAL: verify 'adaptation-community-hammerhead'

5. ssu release update_version
e.g ssu release 2.2.0.29

6. pkcon refresh

7. version --dup #(it will take some time, which depends on your internet speed).

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Once you are done with above procedure reboot your device. You have updated your device to the latest build.