Fix term.verbose without quiet, and vice versa

The match pattern only looked for `Some(false)`, missing `None`.

src/cargo/util/config/mod.rs

@@ -919,8 +919,8 @@ impl Config {
                 (Some(true), Some(true)) => {
                     bail!("cannot set both `term.verbose` and `term.quiet`")
                 }
-                (Some(true), Some(false)) => Verbosity::Verbose,
-                (Some(false), Some(true)) => Verbosity::Quiet,
+                (Some(true), _) => Verbosity::Verbose,
+                (_, Some(true)) => Verbosity::Quiet,
                 _ => Verbosity::Normal,
             },
         };

tests/testsuite/run.rs

@@ -88,6 +88,47 @@ fn verbose_arg_and_quiet_config() {
         .run();
 }
 
+#[cargo_test]
+fn quiet_config_alone() {
+    let p = project()
+        .file(
+            ".cargo/config",
+            r#"
+                [term]
+                quiet = true
+            "#,
+        )
+        .file("src/main.rs", r#"fn main() { println!("hello"); }"#)
+        .build();
+
+    p.cargo("run").with_stderr("").with_stdout("hello").run();
+}
+
+#[cargo_test]
+fn verbose_config_alone() {
+    let p = project()
+        .file(
+            ".cargo/config",
+            r#"
+                [term]
+                verbose = true
+            "#,
+        )
+        .file("src/main.rs", r#"fn main() { println!("hello"); }"#)
+        .build();
+
+    p.cargo("run")
+        .with_stderr(
+            "\
+[COMPILING] foo v0.0.1 ([CWD])
+[RUNNING] `rustc [..]
+[FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
+[RUNNING] `target/debug/foo[EXE]`",
+        )
+        .with_stdout("hello")
+        .run();
+}
+
 #[cargo_test]
 fn quiet_config_and_verbose_config() {
     let p = project()