Revert "busybox: compile with debug information"

This reverts commit 582635b0.

The segfault issue has disappeared, so the workaround is not needed
anymore.

patches/lede/0030-busybox-compile-with-debug-information.patch

-From: Matthias Schiffer <mschiffer@universe-factory.net>
-Date: Mon, 3 Jul 2017 01:40:32 +0200
-Subject: busybox: compile with debug information
-
-The added debug information is stripped of during packaging, so it does not
-increase the package size. It does however slightly change offsets in the
-code, preventing the weird ash segfaults we've been seeing. Also, if the
-issue returns, we'll have debug information matching the coredumps.
-
-diff --git a/package/utils/busybox/Makefile b/package/utils/busybox/Makefile
-index 0d370863653e280165c8083061799af97d031169..5d73e817b3c67225bd3fb4e5b7d86e290db7397b 100644
---- a/package/utils/busybox/Makefile
-+++ b/package/utils/busybox/Makefile
-@@ -91,6 +91,8 @@ ifdef CONFIG_BUSYBOX_DEFAULT_NSLOOKUP_LEDE
-   endif
- endif
- 
-+TARGET_CFLAGS += -g
-+
- define Build/Compile
- 	+$(MAKE) $(PKG_JOBS) -C $(PKG_BUILD_DIR) \
- 		CC="$(TARGET_CC)" \