[libgda] Avoid an implicit fallthrough warning.

[Murray Cumming <murrayc src gnome org>]

commit 6774ed037448da559ce9d8d9237892d20895a483
Author: Murray Cumming <murrayc murrayc com>
Date:   Sun Oct 29 21:13:17 2017 +0100

    Avoid an implicit fallthrough warning.
    
    By adding a break, which seems to be appropriate.
    This function is horribly long. It should really be broken up into
    functions.
    
    This was the warning (with -Werror):
    
    gda-meta-struct.c: In function ‘_meta_struct_complement’:
    gda-meta-struct.c:853:25: error: this statement may fall through [-Werror=implicit-fallthrough=]
      case GDA_META_DB_VIEW: {
                             ^
    gda-meta-struct.c:936:2: note: here
      case GDA_META_DB_TABLE: {
      ^~~~

 libgda/gda-meta-struct.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/libgda/gda-meta-struct.c b/libgda/gda-meta-struct.c
index 849b159..09a6c41 100644
--- a/libgda/gda-meta-struct.c
+++ b/libgda/gda-meta-struct.c
@@ -932,6 +932,7 @@ _meta_struct_complement (GdaMetaStruct *mstruct, GdaMetaDbObjectType type,
 #endif
                        }
                }
+               break;
        }
        case GDA_META_DB_TABLE: {
                /* columns */