Remove 0.6.4 references after the apk got removed

metadata/de.blinkt.openvpn.txt

@@ -9,8 +9,6 @@ Summary:OpenVPN without root
 Description:
 With the VPNService in Android 4.0+ it is possible to create a VPN that doesn't
 need root access. 
-
-N.B. A previous build of 0.6.4 was broken, if you have it installed you may want to reinstall to get the fixed one
 .
 
 Repo Type:hg
@@ -82,21 +80,6 @@ Build:0.6.1,82
         ./misc/build-native.sh
     buildjni=no
 
-Build:0.6.4,85
-    disable=broken build process because of missing source file
-    commit=v0.6.4
-    gradle=yes
-    prebuild=sed -i '/google-breakpad/d' jni/Android.mk && \
-        sed -i -e '/+=.*breakpad/d' -e 's/ [^ ]*breakpad[^ ]*//g' openvpn/Android.mk && \
-        find openvpn/src -type f -print0 | xargs -0 sed -i '/breakpad/d' && \
-        rm -f openvpn/src/openvpn/breakpad.*
-    scandelete=assets
-    build=echo WITH_BREAKPAD=0 >> jni/Android.mk && \
-        sed -i 's/-j 8/-j 4/g' misc/build-native.sh && \
-        sed -e '/HAVE_CONFIG_VERSION_H/ d' -i openvpn/config.h && \
-        ./misc/build-native.sh
-    buildjni=no
-
 Build:0.6.5,86
     commit=v0.6.5
     gradle=yes