[gbrainy] Fixes error with rsvfg library: wrong type on the call

[Jordi Mas <jmas src gnome org>]

commit e9fc74214ad9450078762cc9b6ad38b214370fd4
Author: Jordi Mas <jmas softcatala org>
Date:   Sun Oct 14 21:51:17 2018 +0200

    Fixes error with rsvfg library: wrong type on the call

 src/Core/Libraries/SVGImage.cs | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)
---
diff --git a/src/Core/Libraries/SVGImage.cs b/src/Core/Libraries/SVGImage.cs
index b8cd23d..1c7a1ba 100644
--- a/src/Core/Libraries/SVGImage.cs
+++ b/src/Core/Libraries/SVGImage.cs
@@ -31,7 +31,7 @@ namespace gbrainy.Core.Libraries
                static extern void rsvg_handle_render_cairo (IntPtr Rsvghandle, IntPtr cairo_t);
 
                [DllImport("rsvg-2")]
-               static extern IntPtr rsvg_handle_new_from_file (string file_name, out int error);
+               static extern IntPtr rsvg_handle_new_from_file (string file_name, out GError error);
 
                [DllImport("rsvg-2")]
                static extern void rsvg_handle_free (IntPtr handle);
@@ -40,7 +40,7 @@ namespace gbrainy.Core.Libraries
                static extern void rsvg_handle_get_dimensions (IntPtr handle, ref RsvgDimensionData 
dimension);
 
                [DllImport("rsvg-2")]
-               static extern IntPtr rsvg_handle_new_from_data (byte[] data, int len, out int error);
+               static extern IntPtr rsvg_handle_new_from_data (byte[] data, int len, out GError error);
 
                [StructLayout(LayoutKind.Sequential)]
                struct RsvgDimensionData
@@ -51,6 +51,13 @@ namespace gbrainy.Core.Libraries
                        public double ex;
                }
 
+                struct GError
+                {
+                       public int Domain;
+                       public int Code;
+                       public IntPtr Msg;
+                }
+
                RsvgDimensionData dimension;
                IntPtr handle;
 
@@ -59,7 +66,7 @@ namespace gbrainy.Core.Libraries
                        try {
                                byte[] array;
                                Stream stream;
-                               int error = 0;
+                               GError error;
 
                                stream =  _assembly.GetManifestResourceStream (resource);
                                array = new byte [stream.Length];
@@ -82,7 +89,7 @@ namespace gbrainy.Core.Libraries
        
                public SVGImage (string file)
                {
-                       int error = 0;
+                       GError error;
                        dimension = new RsvgDimensionData ();
 
                        try {