Fix path and VPATH issues of new https/TLS tests

* tests/SSLTest.pm: Use $srcdir in read-only files,
  (_setup_server): Remove unneeded path fixation code
* tests/Test-https-*.px: Use $srcdir for read-only files,
  use $cdir for writable files
* tests/certs/interca.conf: Adjust paths
* tests/certs/rootca.conf: Adjust paths

tests/certs/interca.conf

@@ -7,17 +7,17 @@ authorityKeyIdentifier=keyid:always
 
  [ myca ]
  dir = ./certs/
- new_certs_dir = $dir
+ new_certs_dir = ./
  unique_subject = no
- certificate = $dir/interca.crt
- database = $dir/certindex
- private_key = $dir/interca.key
- serial = $dir/certserial
+ certificate = interca.crt
+ database = certindex
+ private_key = interca.key
+ serial = certserial
  default_days = 730
  default_md = sha1
  policy = myca_policy
  x509_extensions = myca_extensions
- crlnumber = $dir/crlnumber
+ crlnumber = crlnumber
  default_crl_days = 730
 
  [ myca_policy ]