Add debug.txt.1 to .gitignore (#9081)

Desour · SmallJoker · commit 8697090b3564 · 2019-11-02T19:29:14.000+01:00
This should have been done in #8904.
diff --git a/.gitignore b/.gitignore
@@ -55,6 +55,7 @@ gtags.files
 ## Configuration/log files
 minetest.conf
 debug.txt
+debug.txt.1
 
 ## Other files generated by Minetest
 screenshot_*.png
