chore: fix nightly clippy warnings

Author: link2xt

src/html.rs

@@ -144,12 +144,12 @@ impl HtmlMsgParser {
                         self.plain = Some(PlainText {
                             text: decoded_data,
                             flowed: if let Some(format) = mail.ctype.params.get("format") {
-                                format.as_str().to_ascii_lowercase() == "flowed"
+                                format.as_str().eq_ignore_ascii_case("flowed")
                             } else {
                                 false
                             },
                             delsp: if let Some(delsp) = mail.ctype.params.get("delsp") {
-                                delsp.as_str().to_ascii_lowercase() == "yes"
+                                delsp.as_str().eq_ignore_ascii_case("yes")
                             } else {
                                 false
                             },

src/imap.rs

@@ -1913,7 +1913,7 @@ async fn needs_move_to_mvbox(
         && has_chat_version
         && headers
             .get_header_value(HeaderDef::AutoSubmitted)
-            .filter(|val| val.to_ascii_lowercase() == "auto-generated")
+            .filter(|val| val.eq_ignore_ascii_case("auto-generated"))
             .is_some()
     {
         if let Some(from) = mimeparser::get_from(headers) {

src/mimeparser.rs

@@ -1158,7 +1158,7 @@ impl MimeMessage {
 
                         let is_format_flowed = if let Some(format) = mail.ctype.params.get("format")
                         {
-                            format.as_str().to_ascii_lowercase() == "flowed"
+                            format.as_str().eq_ignore_ascii_case("flowed")
                         } else {
                             false
                         };
@@ -1168,7 +1168,7 @@ impl MimeMessage {
                             && is_format_flowed
                         {
                             let delsp = if let Some(delsp) = mail.ctype.params.get("delsp") {
-                                delsp.as_str().to_ascii_lowercase() == "yes"
+                                delsp.as_str().eq_ignore_ascii_case("yes")
                             } else {
                                 false
                             };

src/scheduler.rs

@@ -135,7 +135,7 @@ impl SchedulerState {
     /// If in the meantime [`SchedulerState::start`] or [`SchedulerState::stop`] is called
     /// resume will do the right thing and restore the scheduler to the state requested by
     /// the last call.
-    pub(crate) async fn pause<'a>(&'_ self, context: Context) -> Result<IoPausedGuard> {
+    pub(crate) async fn pause(&'_ self, context: Context) -> Result<IoPausedGuard> {
         {
             let mut inner = self.inner.write().await;
             match *inner {