wscript: Removing unnecessary optimization flag (-O4), which breaks the app

Change-Id: I5751eef4d39c8af8fccb5df6494a2e0f9b614542
diff --git a/wscript b/wscript
index 229824d..db59320 100644
--- a/wscript
+++ b/wscript
@@ -29,7 +29,7 @@
                                                  '-Qunused-arguments'         # only clang supports
                                                  ])
     else:
-        conf.add_supported_cxxflags (cxxflags = ['-O3', '-O4'])
+        conf.add_supported_cxxflags (cxxflags = ['-O3', '-g'])
 
     # I wish I could use it, but there is some weirdness with boost tests. Give up for now
     # try: