corrected branch character

changed ± to 

themes/agnoster.zsh-theme

@@ -90,7 +90,7 @@ prompt_git() {
     zstyle ':vcs_info:*' formats ' %u%c'
     zstyle ':vcs_info:*' actionformats '%u%c'
     vcs_info
-    echo -n "${ref/refs\/heads\//± }${vcs_info_msg_0_}"
+    echo -n "${ref/refs\/heads\// }${vcs_info_msg_0_}"
   fi
 }