patch 9.0.1537: message for opening the cmdline window is not translated

Problem:    Message for opening the cmdline window is not translated.
Solution:   Add gettext() and scan the defaults script for text to be
            translated.  (closes #12371)
diff --git a/src/po/Makefile b/src/po/Makefile
index 9dfbc34..fbe474b 100644
--- a/src/po/Makefile
+++ b/src/po/Makefile
@@ -204,10 +204,12 @@
 	vim.desktop.in
 
 PO_VIM_INPUTLIST = \
-	../../runtime/optwin.vim
+	../../runtime/optwin.vim \
+	../../runtime/defaults.vim
 
 PO_VIM_JSLIST = \
-	optwin.js
+	optwin.js \
+	defaults.js
 
 $(PACKAGE).pot: $(PO_INPUTLIST) $(PO_VIM_INPUTLIST)
 	# Convert the Vim scripts to (what looks like) Javascript
diff --git a/src/po/tojavascript.vim b/src/po/tojavascript.vim
index 7868570..8b0dd73 100644
--- a/src/po/tojavascript.vim
+++ b/src/po/tojavascript.vim
@@ -8,8 +8,9 @@
 for name in argv()[1:]
   exe 'edit ' .. fnameescape(name)
 
-  " Strip comments
+  " Strip comments, also after :set commands.
   g/^\s*"/s/.*//
+  g/^\s*set .*"/s/.*//
 
   " Write as .js file, xgettext recognizes them
   exe 'w! ' .. fnamemodify(name, ":t:r") .. ".js"
diff --git a/src/version.c b/src/version.c
index c8daf71..3a7dcb8 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1537,
+/**/
     1536,
 /**/
     1535,