i18n: fix typos found during l10n for git 2.22.0

Fix two typos introduced by the following commits:

+ 31fba9d3 (diff-parseopt: convert --[src|dst]-prefix, 2019-03-24)
+ ed8b4132 (remote-curl: mark all error messages for translation,
  2019-03-05)
Signed-off-by: NJiang Xin <worldhello.net@gmail.com>
Acked-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

diff.c

@@ -5354,7 +5354,7 @@ static void prep_parse_options(struct diff_options *options)
 			     N_("show the given source prefix instead of \"a/\""),
 			     PARSE_OPT_NONEG),
 		OPT_STRING_F(0, "dst-prefix", &options->b_prefix, N_("<prefix>"),
-			     N_("show the given source prefix instead of \"b/\""),
+			     N_("show the given destination prefix instead of \"b/\""),
 			     PARSE_OPT_NONEG),
 		OPT_CALLBACK_F(0, "line-prefix", options, N_("<prefix>"),
 			       N_("prepend an additional prefix to every line of output"),

remote-curl.c

@@ -1117,13 +1117,13 @@ static void parse_fetch(struct strbuf *buf)
 			const char *q;
 
 			if (parse_oid_hex(p, &old_oid, &q))
-				die(_("protocol error: expected sha/ref, got %s'"), p);
+				die(_("protocol error: expected sha/ref, got '%s'"), p);
 			if (*q == ' ')
 				name = q + 1;
 			else if (!*q)
 				name = "";
 			else
-				die(_("protocol error: expected sha/ref, got %s'"), p);
+				die(_("protocol error: expected sha/ref, got '%s'"), p);
 
 			ref = alloc_ref(name);
 			oidcpy(&ref->old_oid, &old_oid);