GsaApiManager: Remove useless check

This fixes a warning from LGTM:

    This check is useless, getFields cannot be null here,
    since new ArrayList<String>(...) always is non-null.

Signed-off-by: Stefan Weil <sw@weilnetz.de>

src/main/java/org/codelibs/fess/api/gsa/GsaApiManager.java

@@ -260,7 +260,7 @@ public class GsaApiManager extends BaseApiManager implements WebApiManager {
                                 final String tagName =
                                         name.replaceFirst("^" + gsaMetaPrefix, StringUtil.EMPTY).replaceAll(GSA_META_SUFFIX + "\\z",
                                                 StringUtil.EMPTY);
-                                if (getFields != null && getFields.contains(tagName)) {
+                                if (getFields.contains(tagName)) {
                                     buf.append("<MT N=\"");
                                     buf.append(tagName);
                                     buf.append("\" V=\"");