fix(openai): enable image support on OpenAI platform only (fixes #282) (#284)

Signed-off-by: Aaron Pham <contact@aarnphm.xyz>

lua/avante/providers/azure.lua

@@ -13,7 +13,14 @@ local M = {}
 
 M.api_key_name = "AZURE_OPENAI_API_KEY"
 
-M.parse_message = O.parse_message
+M.parse_message = function(opts)
+  local user_content = O.get_user_message(opts)
+  return {
+    { role = "system", content = opts.system_prompt },
+    { role = "user", content = user_content },
+  }
+end
+
 M.parse_response = O.parse_response
 
 M.parse_curl_args = function(provider, code_opts)