Allow running ./tests/testcurl.pl from within git repo.

My first instinct was to run the test script within the checked out
repository.  This small change to the script allows that to work as
expected.

Signed-off-by: Ben Greear <greearb@candelatech.com>

tests/testcurl.pl

@@ -78,6 +78,10 @@ $fixed=0;
 # Determine if we're running from git or a canned copy of curl,
 # or if we got a specific target option or setup file option.
 $CURLDIR="curl";
+if (-f ".git/config") {
+  $CURLDIR = "./";
+}
+
 $git=1;
 $setupfile = 'setup';
 while ($ARGV[0]) {