Use explicit error conversion where there might be ambiguity (payjoin#585)

payjoin#570 (comment)

Author: DanGould

payjoin/src/receive/v2/error.rs

@@ -37,14 +37,6 @@ pub(crate) enum InternalSessionError {
     UnexpectedStatusCode(http::StatusCode),
 }
 
-impl From<crate::into_url::Error> for SessionError {
-    fn from(e: crate::into_url::Error) -> Self { InternalSessionError::ParseUrl(e).into() }
-}
-
-impl From<std::time::SystemTime> for Error {
-    fn from(e: std::time::SystemTime) -> Self { InternalSessionError::Expired(e).into() }
-}
-
 impl From<OhttpEncapsulationError> for Error {
     fn from(e: OhttpEncapsulationError) -> Self {
         InternalSessionError::OhttpEncapsulation(e).into()