gitk: Legacy widgets doesn't have combobox

Use "proc makedroplist" function to support combobox on legacy widgets
mode. "proc makedroplist" uses "ttk::combobox" for themed mode, and uses
"tk_optionMenu" for legacy mode to get rid of the problem.

Signed-off-by: YOKOTA Hiroshi <yokota.hgml@gmail.com>
Signed-off-by: Johannes Sixt <j6t@kdbg.org>

Author: qykth-git

gitk

@@ -11736,13 +11736,11 @@ proc prefspage_general {notebook} {
     grid x $page.tabstopl $page.tabstop -sticky w
 
     ${NS}::label $page.wrapcommentl -text [mc "Wrap comment text"]
-    ${NS}::combobox $page.wrapcomment -values {none char word} -state readonly \
-        -textvariable wrapcomment
+    makedroplist $page.wrapcomment wrapcomment none char word
     grid x $page.wrapcommentl $page.wrapcomment -sticky w
 
     ${NS}::label $page.wrapdefaultl -text [mc "Wrap other text"]
-    ${NS}::combobox $page.wrapdefault -values {none char word} -state readonly \
-        -textvariable wrapdefault
+    makedroplist $page.wrapdefault wrapdefault none char word
     grid x $page.wrapdefaultl $page.wrapdefault -sticky w
 
     ${NS}::checkbutton $page.ntag -text [mc "Display nearby tags/heads"] \