Fix syntax error on authMethods in java retrofit client

[xhh]

For example, the following Petstore code generated with the latest master does not compile:

for(String authName : authNames) {
    if (apiAuthorizations.containsKey(authName)) {
        throw new RuntimeException("auth name \"" + authName + "\" already in api authorizations");
    }
    Interceptor auth;
    if (authName == "petstore_auth") { 
        auth = new OAuth(OAuthFlow.implicit, "http://petstore.swagger.io/api/oauth/dialog", "", "write:pets, read:pets");
    } else {
        throw new RuntimeException("auth name \"" + authName + "\" not found in available auth names");
    }
    apiAuthorizations.put(authName, auth);
    Interceptor auth;
    if (authName == "api_key") { 
        auth = new ApiKeyAuth("header", "api_key");
    } else {
        throw new RuntimeException("auth name \"" + authName + "\" not found in available auth names");
    }
    apiAuthorizations.put(authName, auth);
}

This PR changes it to:

for(String authName : authNames) {
    if (apiAuthorizations.containsKey(authName)) {
        throw new RuntimeException("auth name \"" + authName + "\" already in api authorizations");
    }
    Interceptor auth;
    if (authName == "petstore_auth") { 
        auth = new OAuth(OAuthFlow.implicit, "http://petstore.swagger.io/api/oauth/dialog", "", "write:pets, read:pets");
    } else if (authName == "api_key") { 
        auth = new ApiKeyAuth("header", "api_key");
    } else {
        throw new RuntimeException("auth name \"" + authName + "\" not found in available auth names");
    }
    apiAuthorizations.put(authName, auth);
}