pip: fix indexes URL (#6986)

Fixes #6981. 

plugins/pip/pip.plugin.zsh

@@ -10,7 +10,7 @@
 # "zsh-pip-clear-cache".
 
 ZSH_PIP_CACHE_FILE=~/.pip/zsh-cache
-ZSH_PIP_INDEXES=(https://pypi.python.org/simple/)
+ZSH_PIP_INDEXES=(https://pypi.org/simple/)
 
 zsh-pip-clear-cache() {
   rm $ZSH_PIP_CACHE_FILE
@@ -31,7 +31,7 @@ zsh-pip-cache-packages() {
       tmp_cache=/tmp/zsh_tmp_cache
       for index in $ZSH_PIP_INDEXES ; do
           # well... I've already got two problems
-          curl $index 2>/dev/null | \
+          curl -L $index 2>/dev/null | \
               zsh-pip-clean-packages \
                >> $tmp_cache
       done