dependencies: bumped GIT to 2.17.2 to address the security issues found in GIT

pkgs/overlays.nix

@@ -1,45 +1,45 b''
 self: super: {
   # bump GIT version
   git = super.lib.overrideDerivation super.git (oldAttrs: {
-    name = "git-2.17.1";
+    name = "git-2.17.2";
     src = self.fetchurl {
-      url = "https://www.kernel.org/pub/software/scm/git/git-2.17.1.tar.xz";
-      sha256 = "0pm6bdnrrm165k3krnazxcxadifk2gqi30awlbcf9fism1x6w4vr";
+      url = "https://www.kernel.org/pub/software/scm/git/git-2.17.2.tar.xz";
+      sha256 = "1ghljlxmyqphx13qspy382cpl2pbkbwbhqm7w7z57r9mkhswx668";
     };
 
     patches = [
       ./git_patches/docbook2texi.patch
       ./git_patches/symlinks-in-bin.patch
       ./git_patches/git-sh-i18n.patch
       ./git_patches/ssh-path.patch
     ];
 
   });
 
   # Override subversion derivation to
   #  - activate python bindings
   subversion =
   let
     subversionWithPython = super.subversion.override {
       httpSupport = true;
       pythonBindings = true;
       python = self.python27Packages.python;
     };
   in
     super.lib.overrideDerivation subversionWithPython (oldAttrs: {
       name = "subversion-1.10.2";
       src = self.fetchurl {
         url = "https://archive.apache.org/dist/subversion/subversion-1.10.2.tar.gz";
         sha256 = "0xv5z2bg0lw7057g913yc13f60nfj257wvmsq22pr33m4syf26sg";
       };
 
       ## use internal lz4/utf8proc because it is stable and shipped with SVN
       configureFlags = oldAttrs.configureFlags ++ [
         " --with-lz4=internal"
         " --with-utf8proc=internal"
       ];
 
 
   });
 
 }