curl, git: Fix curl default CA, let git use it

Improve patching of curl to use NIX_SSL_CERT_FILE as default CA
Remove patches from git, as git uses curl and passes its environment
variables to curl.

pkgs/applications/version-management/git-and-tools/git/default.nix

@@ -30,7 +30,6 @@ stdenv.mkDerivation {
     ./symlinks-in-bin.patch
     ./git-sh-i18n.patch
     ./ssh-path.patch
-    ./ssl-cert-file.patch
   ];
 
   postPatch = ''

pkgs/applications/version-management/git-and-tools/git/ssl-cert-file.patch

@@ -1,14 +0,0 @@
-diff -ru git-2.7.4-orig/http.c git-2.7.4/http.c
---- git-2.7.4-orig/http.c	2016-03-17 21:47:59.000000000 +0100
-+++ git-2.7.4/http.c	2016-04-12 11:38:33.187070848 +0200
-@@ -544,6 +544,10 @@
- #if LIBCURL_VERSION_NUM >= 0x070908
- 	set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
- #endif
-+	if (getenv("NIX_SSL_CERT_FILE"))
-+	  set_from_env(&ssl_cainfo, "NIX_SSL_CERT_FILE");
-+	else
-+	  set_from_env(&ssl_cainfo, "SSL_CERT_FILE");
- 	set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
- 
- 	set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");