configure.ac: Require libosmocore 1.2.0

Current code uses GSM23003_MSISDN_MAX_DIGITS, which is only available in
libosmocore 1.2.0 onwards. Let's update configure.ac accordingly.

Fixes: 2e403d6c3f0caa4fd40e8cab8acd6586deadfdf8
Change-Id: Iad03a8cf7a36bdc824ec2acc8fb8f9c27a1c0421
diff --git a/configure.ac b/configure.ac
index ef703f2..993d4d5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -34,10 +34,10 @@
 
 PKG_CHECK_MODULES(TALLOC, [talloc >= 2.0.1])
 
-PKG_CHECK_MODULES(LIBOSMOCORE, libosmocore >= 1.0.0)
-PKG_CHECK_MODULES(LIBOSMOGSM, libosmogsm >= 1.0.0)
-PKG_CHECK_MODULES(LIBOSMOVTY, libosmovty >= 1.0.0)
-PKG_CHECK_MODULES(LIBOSMOCTRL, libosmoctrl >= 1.0.0)
+PKG_CHECK_MODULES(LIBOSMOCORE, libosmocore >= 1.2.0)
+PKG_CHECK_MODULES(LIBOSMOGSM, libosmogsm >= 1.2.0)
+PKG_CHECK_MODULES(LIBOSMOVTY, libosmovty >= 1.2.0)
+PKG_CHECK_MODULES(LIBOSMOCTRL, libosmoctrl >= 1.2.0)
 PKG_CHECK_MODULES(LIBOSMOABIS, libosmoabis >= 0.6.0)
 
 PKG_CHECK_MODULES(SQLITE3, sqlite3)