Use an appropriate *server* URL in the generated authentication file instead of a *product* URL

[whisperity]

As reported by @RobertoFioravanti in Ericsson/codechecker#4025, the automatically generated .codechecker.passwords.json contains the raw product URL instead of a server URL and this makes the action rely on undocumented happenstance in CodeChecker to be able to log in:

CodeChecker-Action/src/store-pre.sh

Line 17 in c1fbda0

"$IN_STORE_URL": "$IN_STORE_USERNAME:$IN_STORE_PASSWORD"

[RobertoFioravanti]

It seems to work correctly by applying this regex to "$IN_STORE_URL" in store-pre.sh:
^((https?:\/\/)?([^\/]+)([\/].+))\/([^\/]+)$:

• The server url is given by "${BASH_REMATCH[1]}".
• The product is given by "${BASH_REMATCH[5]}"}.

Credentials wold become
"${BASH_REMATCH[1]}": "$IN_STORE_USERNAME:$IN_STORE_PASSWORD".