Update error message in ProtocolVersion

Error message for Protocol Major Version was incorrect.

Author: Mavelous

httpcore5/src/main/java/org/apache/hc/core5/http/ProtocolVersion.java

@@ -71,7 +71,7 @@ public class ProtocolVersion implements Serializable {
      */
     public ProtocolVersion(final String protocol, final int major, final int minor) {
         this.protocol = Args.notNull(protocol, "Protocol name");
-        this.major = Args.notNegative(major, "Protocol minor version");
+        this.major = Args.notNegative(major, "Protocol major version");
         this.minor = Args.notNegative(minor, "Protocol minor version");
     }