patch 8.1.2082: some files have a weird name to fit in 8.3 characters

Problem:    Some files have a weird name to fit in 8.3 characters.
Solution:   Use a nicer names.
diff --git a/src/INSTALLpc.txt b/src/INSTALLpc.txt
index c72875a..ce80a9a 100644
--- a/src/INSTALLpc.txt
+++ b/src/INSTALLpc.txt
@@ -1023,7 +1023,7 @@
   Move the "vim81" subdirectory into the subdirectory where you want Vim
   to be installed.  Typically, this subdirectory will be named "vim".
   If you already have a "vim81" subdirectory in "vim", delete it first
-  by running its uninstal.exe program.
+  by running its uninstall.exe program.
 
   E.  Install Vim
   ---------------