patch 8.2.0744: the name vim is not capatilized in a message

Problem:    The name vim is not capatilized in a message.
Solution:   Use "Vim" instead of "vim".
diff --git a/src/main.c b/src/main.c
index a1e933c..b00d7b9 100644
--- a/src/main.c
+++ b/src/main.c
@@ -3600,7 +3600,7 @@
 #  endif
 # endif
     main_msg(_("-display <display>\tRun Vim on <display>"));
-    main_msg(_("-iconic\t\tStart vim iconified"));
+    main_msg(_("-iconic\t\tStart Vim iconified"));
     main_msg(_("-background <color>\tUse <color> for the background (also: -bg)"));
     main_msg(_("-foreground <color>\tUse <color> for normal text (also: -fg)"));
     main_msg(_("-font <font>\t\tUse <font> for normal text (also: -fn)"));