bugfix cas-168 update does not overwrite nil fields

[0xmovses]

the avatar, or Logo field was being overwritten with nil on update if a value was not sent in the payload. This has been fixed by using the COALESCE keyword in the sql UpdateCommunity models function

[germanurrus]

For some reason now name is not updating:
Sending this:

{
    "name": "Update Name",
    "signingAddr": "0xf8d6e0586b0a20c7",
    "timestamp": "1656696627669",
    "compositeSignatures": [
        {
            "addr": "0xf8d6e0586b0a20c7",
            "keyId": 0,
            "signature": "f53e3ac4cf37954c4c055824d748b4cdb354ba2cc18835d2d7d9d1159a423706d24d8889e8344b48c708e3e9916131962b5f64f7f61dfd35d4661c6fbbdc61f6"
        }
    ]
}

and response is:

{
"id":2,
   "name":"sds",
   "logo":"https://gateway.pinata.cloud/ipfs/QmdjLkYuDhxeJirgTiyAjJk2kw8nvjJyM8tWi7c3hAPmio",
   "onlyAuthorsToSubmit":false,
   "slug":"a42891b85e",
   "contractName":"11",
   "timestamp":"",
   "compositeSignatures":null,
   "creatorAddr":"0xf8d6e0586b0a20c7",
   "createdAt":"2022-07-01T17:13:25.645701Z",
   "cid":"QmWy3NUoteCoB1stj8fMHUSQAkLyBfEikrqWGVB2yZfsND"
}

[0xmovses]

checking this now

[0xmovses]

fixed. can you test again @germanurrus ?

[germanurrus]

fixed. can you test again @germanurrus ?

Tested again and works.