[gtksourceviewmm] SearchContext: Use const_iterator where appropriate.

[Murray Cumming <murrayc src gnome org>]

commit 7b7aa5652b53b340927f951b992fdff47ad8cba9
Author: Murray Cumming <murrayc murrayc com>
Date:   Fri Mar 31 14:18:43 2017 +0200

    SearchContext: Use const_iterator where appropriate.

 gtksourceview/src/searchcontext.hg |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/gtksourceview/src/searchcontext.hg b/gtksourceview/src/searchcontext.hg
index 0220098..ebda26b 100644
--- a/gtksourceview/src/searchcontext.hg
+++ b/gtksourceview/src/searchcontext.hg
@@ -130,7 +130,7 @@ public:
    *
    * @newin{3,10}
    */
-  _WRAP_METHOD(int get_occurrence_position(const TextBuffer::iterator& match_start, const 
TextBuffer::iterator& match_end) const, gtk_source_search_context_get_occurrence_position)
+  _WRAP_METHOD(int get_occurrence_position(const TextBuffer::const_iterator& match_start, const 
TextBuffer::const_iterator& match_end) const, gtk_source_search_context_get_occurrence_position)
 
   /** Synchronous forward search. It is recommended to use the asynchronous functions instead, to not block 
the user interface. However, if you are sure that
    * the buffer is small, this function is more convenient to use.
@@ -142,7 +142,7 @@ public:
    *
    * @newin{3,10}
    */
-  _WRAP_METHOD(bool forward(const TextBuffer::iterator& iter, TextBuffer::iterator& match_start, 
TextBuffer::iterator& match_end, bool& has_wrapped_around), gtk_source_search_context_forward2)
+  _WRAP_METHOD(bool forward(const TextBuffer::const_iterator& iter, TextBuffer::iterator& match_start, 
TextBuffer::iterator& match_end, bool& has_wrapped_around), gtk_source_search_context_forward2)
   _IGNORE(gtk_source_search_context_forward)
 
   /** Asynchronous forward search. See the GAsyncResult documentation to know how to use this function.