DOCS: Corrected IMAP URL examples according to RFC5092

URL examples that included the UID weren't technically correct although
would pass the curl parser.
diff --git a/docs/libcurl/curl_easy_setopt.3 b/docs/libcurl/curl_easy_setopt.3
index 2e59b17..72fc89f 100644
--- a/docs/libcurl/curl_easy_setopt.3
+++ b/docs/libcurl/curl_easy_setopt.3
@@ -748,10 +748,10 @@
 imap://user:password@mail.example.com/OUTBOX - Selects the user's OUTBOX and
 fetches message 1.
 
-imap://user:password@mail.example.com/OUTBOX;UID=2 - Selects the user's OUTBOX
+imap://user:password@mail.example.com/OUTBOX/;UID=2 - Selects the user's OUTBOX
 mailbox and fetches message 2
 
-imap://user:password@mail.example.com/OUTBOX;UID=3/;SECTION=TEXT - Selects the
+imap://user:password@mail.example.com/OUTBOX/;UID=3/;SECTION=TEXT - Selects the
 SENT mailbox and fetches message 3 with only the text portion of the message
 
 For more information about the individual components of an IMAP URL please