bump product version to 7.6.0.0.alpha0+

Change-Id: I4cc88c54d42dd141f03c46377cd5c2f2fa56ad7b
diff --git a/configure.ac b/configure.ac
index 1e85063..5fc489a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -9,7 +9,7 @@ dnl in order to create a configure script.
# several non-alphanumeric characters, those are split off and used only for the
# ABOUTBOXPRODUCTVERSIONSUFFIX in openoffice.lst. Why that is necessary, no idea.

AC_INIT([LibreOffice],[7.5.0.0.alpha1+],[],[],[http://documentfoundation.org/])
AC_INIT([LibreOffice],[7.6.0.0.alpha0+],[],[],[http://documentfoundation.org/])

dnl libnumbertext needs autoconf 2.68, but that can pick up autoconf268 just fine if it is installed
dnl whereas aclocal (as run by autogen.sh) insists on using autoconf and fails hard