Revert "[Preferences] Button problem in Preferences arduino#9185"

This reverts commit 3def4aa.

Author: yzykov

app/src/cc/arduino/view/preferences/Preferences.java

@@ -218,7 +218,6 @@ public void actionPerformed(java.awt.event.ActionEvent evt) {
     additionalBoardsManagerField.setToolTipText(tr("Enter a comma separated list of urls"));
 
     extendedAdditionalUrlFieldWindow.setIcon(new ImageIcon(Theme.getThemeImage("newwindow", this, Theme.scale(16), Theme.scale(14))));
-    extendedAdditionalUrlFieldWindow.setToolTipText(tr("Enter additional URLs, one for each row"));
     extendedAdditionalUrlFieldWindow.setMargin(new java.awt.Insets(1, 1, 1, 1));
     extendedAdditionalUrlFieldWindow.addActionListener(new java.awt.event.ActionListener() {
       public void actionPerformed(java.awt.event.ActionEvent evt) {