refactor(config): use correct data type for server-cors-allowed-origins

Replaces the `Maybe [Text]` with `[Text]`. The `Maybe` is unnecessary
because we handle `Just []` and `Nothing` the same way.

Signed-off-by: Taimoor Zaeem <taimoorzaeem@gmail.com>

test/spec/SpecHelper.hs

@@ -146,7 +146,7 @@ baseCfg = let secret = encodeUtf8 "reallyreallyreallyreallyverysafe" in
   , configOpenApiMode               = OAFollowPriv
   , configOpenApiSecurityActive     = False
   , configOpenApiServerProxyUri     = Nothing
-  , configServerCorsAllowedOrigins  = Nothing
+  , configServerCorsAllowedOrigins  = []
   , configServerHost                = "localhost"
   , configServerPort                = 3000
   , configServerTraceHeader         = Nothing