Remove unused import

Author: Mykola Mokhnach

src/main/java/io/appium/java_client/MobileCommand.java

@@ -22,7 +22,6 @@
 import org.openqa.selenium.remote.CommandInfo;
 import org.openqa.selenium.remote.http.HttpMethod;
 
-import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
 import java.time.Duration;
 import java.util.AbstractMap;