build: require gcc >= 5.3

Change-Id: Ie8877a9047c96030f138745a19768fcfa11da855
Refs: #4462

wscript

@@ -83,7 +83,7 @@ def version(ctx):
             else:
                 # no tags matched
                 Context.g_module.VERSION = '%s-commit-%s' % (VERSION_BASE, out)
-    except subprocess.CalledProcessError:
+    except (OSError, subprocess.CalledProcessError):
         pass
 
     versionFile = ctx.path.find_node('VERSION')