remove extraneous text from example config

Author: tshepang

config.example.toml

@@ -829,7 +829,7 @@
 # target triples containing `-none`, `nvptx`, `switch`, or `-uefi`.
 #no-std = <platform-specific> (bool)
 
-# This is an array of the codegen backends that will be compiled a rustc
+# This is an array of the codegen backends that will be
 # compiled for this target, overriding the global rust.codegen-backends option.
 # See that option for more info.
 #codegen-backends = rust.codegen-backends (array)