[glom] Field::sql_find_operator(): Add a fallback return.

[Murray Cumming <murrayc src gnome org>]

commit 3760c2043850a28dbd7553089a73bcd934abedb9
Author: Murray Cumming <murrayc murrayc com>
Date:   Thu Feb 4 22:49:08 2016 +0100

    Field::sql_find_operator(): Add a fallback return.
    
    The (now C++14) compiler seems to want this now, even though our
    default switch case should be enough.

 glom/libglom/data_structure/field.cc |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/glom/libglom/data_structure/field.cc b/glom/libglom/data_structure/field.cc
index 516f9da..3ea56f1 100644
--- a/glom/libglom/data_structure/field.cc
+++ b/glom/libglom/data_structure/field.cc
@@ -459,6 +459,8 @@ Gnome::Gda::SqlOperatorType Field::sql_find_operator() const
       return Gnome::Gda::SQL_OPERATOR_TYPE_EQ;
     }
   }
+
+  return Gnome::Gda::SQL_OPERATOR_TYPE_EQ;
 }