main: Change `unwrap` to `expect`

Give us a better error message if a failure ever happens here. Was
inspired by my experience in 2d1f7031f03194fbceffc15b1d6376abea243e22,
where the `unwrap` calls gave no useful information.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/main.rs b/src/main.rs
index 0732f6d..e2e0030 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -26,7 +26,7 @@ fn main() {
     let stdin = io::stdin();
 
     for line in stdin.lock().lines() {
-        let line = line.unwrap();
+        let line = line.expect("Error reading from STDIN");
 
         // Write the message to STDOUT so that it can be properly read by Mutt
         println!("{}", line);