Exit ollama code

Author: tharun571

src/xmagics/xassist.cpp

@@ -326,6 +326,12 @@ namespace xcpp
             return "";
         }
 
+        if (url.empty())
+        {
+            std::cerr << "URL not found." << std::endl;
+            return "";
+        }
+
         const std::string post_data = R"({
                     "model": ")" + model
                                       + R"(",