shellcheck fixes

* Script: https://github.com/koalaman/shellcheck
* Use $(..) instead of deprecated `..`
* Use double quote to prevent globbing and word splitting.

Change-Id: I68372d4e29ae34e0704e5a605447ad17bf0666d7

scripts/update-jquery-i18n.sh

@@ -2,7 +2,7 @@
 
 DEST="../lib/jquery.i18n";
 CLONEDIR="/tmp/jquery.i18n";
-HERE=`pwd`;
+HERE=$(pwd);
 UPSTREAM="https://github.com/wikimedia/jquery.i18n.git";
 
 echo -e "Getting latest jquery.i18n from $UPSTREAM\n";
@@ -13,5 +13,5 @@ else
     git clone $UPSTREAM $CLONEDIR;
 fi
 
-cd $HERE;
+cd "$HERE";
 cp -rf $CLONEDIR/src/* $DEST