config: fix some small capitalization issues, as spotted

Fix some small capitalization issues, as spotted while going through the
documentation.  In general, a semicolon doesn't start a new sentence, and
"this" has no meaning of a proper noun in this context.

Signed-off-by: Dragan Simic <dsimic@manjaro.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Documentation/config/core.txt b/Documentation/config/core.txt
index 73430b6..c505388 100644
--- a/Documentation/config/core.txt
+++ b/Documentation/config/core.txt
@@ -554,7 +554,7 @@
 	will not overwrite existing objects.
 +
 On some file system/operating system combinations, this is unreliable.
-Set this config setting to 'rename' there; However, This will remove the
+Set this config setting to 'rename' there; however, this will remove the
 check that makes sure that existing object files will not get overwritten.
 
 core.notesRef::