Use DECIMAL instead of INTEGER when casting as mysql doesn't work with just...

Use DECIMAL instead of INTEGER when casting as mysql doesn't work with just "INTEGER" and other databases don't like "UNSIGNED" which mysql requires

And don't mask exceptions.
Signed-off-by: NJeremy Kemper <jeremy@bitsweat.net>

activerecord/lib/active_record/migration.rb

@@ -407,9 +407,14 @@ def schema_migrations_table_name
       end
 
       def current_version
-        Base.connection.select_value(
-          "SELECT MAX(CAST(version AS integer)) FROM #{schema_migrations_table_name}"
-        ).to_i rescue 0
+        sm_table = schema_migrations_table_name
+        if Base.connection.table_exists?(sm_table)
+          Base.connection.select_value(
+            "SELECT MAX(CAST(version AS DECIMAL)) FROM #{sm_table}"
+          ).to_i
+        else
+          0
+        end
       end
 
       def proper_table_name(name)