chore: remove duplicate setting of header params

client/client.go

@@ -143,7 +143,7 @@ func (c *Client) SendRequest(method string, rawURL string, data url.Values,
 
 	//For HTTP GET Method there are no body parameters. All other parameters like query, path etc
 	// are added as information in the url itself. Also while Content-Type is json, we are sending
-	// json body. In that case, data variable conatins all other parameters than body, which is the
+	// json body. In that case, data variable contains all other parameters than body, which is the
 	//same case as GET method. In that case as well all parameters will be added to url
 	if method == http.MethodGet || contentType == jsonContentType {
 		if data != nil {
@@ -178,10 +178,6 @@ func (c *Client) SendRequest(method string, rawURL string, data url.Values,
 
 	}
 
-	if contentType == urlEncodedContentType {
-		req.Header.Add("Content-Type", urlEncodedContentType)
-	}
-
 	req.SetBasicAuth(c.basicAuth())
 
 	// E.g. "User-Agent": "twilio-go/1.0.0 (darwin amd64) go/go1.17.8"