credential.c: fix credential reading with regards to CR/LF

This fix makes using Git credentials more friendly to Windows users. In
previous version it was unable to finish input correctly without
configuration changes (tested in PowerShell, CMD, Cygwin).

We know credential filling should be finished by empty input, but the
current implementation does not take into account CR/LF ending, and
hence instead of the empty string we get '\r', which is interpreted as
an incorrect string.

So this commit changes default reading function to a more Windows
compatible reading function.

Signed-off-by: Nikita Leonov <nykyta.leonov@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

credential.c

@@ -202,7 +202,7 @@ int credential_read(struct credential *c, FILE *fp)
 {
 	struct strbuf line = STRBUF_INIT;
 
-	while (strbuf_getline_lf(&line, fp) != EOF) {
+	while (strbuf_getline(&line, fp) != EOF) {
 		char *key = line.buf;
 		char *value = strchr(key, '=');