typo in INSTALL.sgi

[david l goodrich <dlg_(_at_)_dorkzilla_(_dot_)_org>]

there's a typo in INSTALL.sgi.  see the below diff:

--- INSTALL.sgi Fri Jan 21 19:19:14 2005
+++ INSTALL.sgi Fri Jan 21 19:19:28 2005
@@ -483,7 +483,7 @@

     The first time the Maintenance Console is entered, it may be
     necessary to force a reset of the environment to its default
-    settings by entering the ``resetenv'' command and the chevron
+    settings by entering the ``resetenv'' command at the chevron
     prompt. If some variables have been set explicitly, this may
     disturb the normal OpenBSD boot process.