fix

Author: wing328

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractScalaCodegen.java

@@ -529,16 +529,22 @@ protected String formatIdentifier(String name, boolean capitalized) {
         if (identifier.matches("[a-zA-Z_$][\\w_$]+") && !isReservedWord(identifier)) {
             return identifier;
         }
-        if (identifier.matches("[0-9]*")) {
-            return escapeReservedWord(identifier);
-        }
-        if (!capitalized || StringUtils.isNumeric(name)) {
-            // starts with a small letter, could be a keyword or a number
-            return escapeReservedWord(identifier);
-        } else {
-            // no keywords start with large letter
-            return identifier;
+
+	// below code block only for scala-sttp4-jsoniter for backward copmatibility
+        if (this instanceof ScalaSttp4JsoniterClientCodegen) {
+            if (identifier.matches("[0-9]*")) {
+                return escapeReservedWord(identifier);
+            }
+            if (!capitalized || StringUtils.isNumeric(name)) {
+                // starts with a small letter, could be a keyword or a number
+                return escapeReservedWord(identifier);
+            } else {
+                // no keywords start with large letter
+                return identifier;
+            }
         }
+
+	return escapeReservedWord(identifier);
     }
 
     protected String stripPackageName(String input) {