Auto merge of #4528 - adrian5:patch-1, r=alexcrichton
Auto merge of #4528 - adrian5:patch-1, r=alexcrichton

Fix typo in doc

tshepang/cargo,rustyhorde/cargo,tsurai/cargo,tshepang/cargo,rustyhorde/cargo,vojtechkral/cargo,tsurai/cargo,rust-lang/cargo,nipunn1313/cargo,rustyhorde/cargo,eminence/cargo,achanda/cargo,eminence/cargo,tsurai/cargo,achanda/cargo,eminence/cargo,tshepang/cargo,vojtechkral/cargo,tshepang/cargo,rust-lang/cargo,rust-lang/cargo,vojtechkral/cargo,tsurai/cargo,rustyhorde/cargo,nipunn1313/cargo,eminence/cargo,achanda/cargo,nipunn1313/cargo,nipunn1313/cargo,rust-lang/cargo,tsurai/cargo,vojtechkral/cargo,achanda/cargo