[latexila] Adapt the HACKING instructions

[SÃbastien Wilmet <swilmet src gnome org>]

commit be24d32745844d9487d25fce6902f1ab07e84222
Author: SÃbastien Wilmet <swilmet gnome org>
Date:   Tue Sep 4 21:31:49 2012 +0200

    Adapt the HACKING instructions

 HACKING |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)
---
diff --git a/HACKING b/HACKING
index 19c3332..c78fef3 100644
--- a/HACKING
+++ b/HACKING
@@ -48,11 +48,9 @@ There are some rules to follow when coding:
       line and then the description
     - same coding style everywhere
 
-How to generate the C code from Vala files?
-    See the file "INSTALL".
-
 How to debug LaTeXila with gdb?
-    Run CMake with this option: -DCMAKE_BUILD_TYPE=Debug
+    Run:
+    $ make CFLAGS="-g"
 
     Here is how you can get the backtrace after a crash:
     $ gdb ./latexila