Fix tab order in FindReplace

When searching through all tabs, the order was accidentally reversed.
This was broken by commit d2bac86 (Remove tab switching logic from
Sketch).

This also fixes a problem where "replace all" would only work on the
first and last tab (since it would search backwards from the first tab
to the last tab and then conclude it was done).

This fixes a part of arduino#5380.

app/src/cc/arduino/view/findreplace/FindReplace.java

@@ -345,12 +345,12 @@ private boolean find(boolean wrap, boolean backwards, boolean searchTabs, int or
             }
 
             if (backwards) {
-              editor.selectNextTab();
+              editor.selectPrevTab();
               this.setVisible(true);
               int l = editor.getCurrentTab().getText().length() - 1;
               editor.getCurrentTab().setSelection(l, l);
             } else {
-              editor.selectPrevTab();
+              editor.selectNextTab();
               this.setVisible(true);
               editor.getCurrentTab().setSelection(0, 0);
             }