Bug #37712 --> "Receiving: message headers" should be "Downloading message headers 123 of 1323"

Patch by tmeader@gmail.com

sr=mscott/bienvenu

mail/locales/en-US/chrome/messenger/imapMsgs.properties

@@ -189,14 +189,14 @@
 # Place the word %S in your translation where the name of the server should appear.
 # Place the word %lu where the number of headers should appear.
 
-5036=%S Receiving: Message headers %lu of %lu
+5036=%S Downloading message header %lu of %lu
 
 ## @name IMAP_RECEIVING_MESSAGE_FLAGS_OF
 ## @loc None
 # LOCALIZATION NOTE (Error 5037): Do not translate the word "%S" or "%lu" below.
 # Place the word %S in your translation where the name of the server should appear.
 # Place the word %lu where the number of flags should appear.
-5037=%S Receiving: Message flags %lu of %lu
+5037=%S Downloading message flag %lu of %lu
 
 ## @name IMAP_DELETING_MESSAGES
 ## @loc None
@@ -242,7 +242,7 @@
 # LOCALIZATION NOTE (Error 5045): Do not translate the word "%S" or "%lu" below.
 # Place the word %S in your translation where the name of the folder should appear.
 # Place the word %lu where the number of headers should appear.
-5045=%S - Receiving: message %lu of %lu
+5045=%S - Downloading message %lu of %lu
 
 ## @name IMAP_DISCOVERING_MAILBOX 
 ## @loc None

mail/locales/en-US/chrome/messenger/localMsgs.properties

@@ -66,7 +66,7 @@
 # Place the word %lu where the number of messages should appear.
 # The first %lu will receive the number of messages received so far;
 # the second %lu will receive the total number of messages
-4002=Receiving: message %S of %S
+4002=Downloading message %S of %S
 
 # Status - pop3 server error
 ## @name POP3_SERVER_ERROR