patch 8.2.0828: Travis: regexp patttern doesn't work everywhere
Problem: Travis: regexp patttern doesn't work everywhere.
Solution: Use [:blank:] instead of \b. (Ozaki Kiichi, closes #6146)
diff --git a/ci/config.mk.sed b/ci/config.mk.sed
index 3168278..cd2cd9c 100644
--- a/ci/config.mk.sed
+++ b/ci/config.mk.sed
@@ -1,2 +1,2 @@
-/^CFLAGS\b/s/$/ -Wall -Wextra -Wshadow -Werror/
-/^PERL_CFLAGS\b/s/$/ -Wno-error=unused-function/
+/^CFLAGS[[:blank:]]*=/s/$/ -Wall -Wextra -Wshadow -Werror/
+/^PERL_CFLAGS[[:blank:]]*=/s/$/ -Wno-error=unused-function/