Remove not null constraint. Fix #2976

db_structure.xml

@@ -910,7 +910,6 @@
 				<name>displayname</name>
 				<type>text</type>
 				<default></default>
-				<notnull>true</notnull>
 				<length>64</length>
 			</field>
 

lib/util.php

@@ -75,7 +75,7 @@ class OC_Util {
 	public static function getVersion() {
 		// hint: We only can count up. Reset minor/patchlevel when
 		// updating major/minor version number.
-		return array(5, 80, 01);
+		return array(5, 80, 02);
 	}
 
 	/**