Remove duplicated autogen.sh entry in default ignores #5316

The key and value are identical on both lines, so this is a dead line
rather than a behaviour change.

Signed-off-by: Daksha1611 <mehtadaksha1611@gmail.com>

Author: Daksha1611

src/commoncode/ignore.py

@@ -202,7 +202,6 @@ def get_ignores(location, include_defaults=True):
     "stamp-h1": "Default ignore: autoconf artifact",
     "m4/": "Default ignore: autoconf artifact",
     "autogen.sh": "Default ignore: autotools artifact",
-    "autogen.sh": "Default ignore: autotools artifact",
     "CMakeCache.txt": "Default ignore: CMake artifact",
     "cmake_install.cmake": "Default ignore: CMake artifact",
     "install_manifest.txt": "Default ignore: CMake artifact",