Allow make clean removing files to fail

These files might not exist for various reasons, such as
a partial install or previous inplace install.
They might also have wrong permissions, for example, when
they were installed as root.

Makefile

@@ -292,8 +292,8 @@ inplace-postinstall-nginx: inplace-postinstall-permissions
 
 # Removes created symlinks; generated logs, submissions, etc. remain in output subdir.
 inplace-uninstall-l:
-	rm -rf $(judgehost_libjudgedir)
-	rm -rf $(judgehost_bindir)
+	-rm -rf $(judgehost_libjudgedir)
+	-rm -rf $(judgehost_bindir)
 
 # Rules to configure and build for a Coverity scan.
 coverity-conf:

misc-tools/Makefile

@@ -43,7 +43,7 @@ inplace-install-l:
 
 inplace-uninstall-l:
 # bindir gets removed from the main Makefile
-	rm -f $(domserver_libdir)/dj_utils.py
+	-rm -f $(domserver_libdir)/dj_utils.py
 
 clean-l:
 	-rm -f $(TARGETS) $(OBJECTS)