Fixing upgrade scripts for ASSIGNEE_ column type modification

modules/activiti-engine/src/main/resources/org/activiti/db/upgrade/activiti.db2.upgradestep.514.to.515.history.sql

@@ -33,6 +33,6 @@ alter table ACT_HI_TASKINST
     
 Call Sysproc.admin_cmd ('REORG TABLE ACT_HI_TASKINST');      
 
-alter table ACT_HI_ACTINST alter column ASSIGNEE_ varchar(255);
+alter table ACT_HI_ACTINST alter column ASSIGNEE_ SET DATA TYPE varchar(255);
 
 Call Sysproc.admin_cmd ('REORG TABLE ACT_HI_ACTINST');
\ No newline at end of file

modules/activiti-engine/src/main/resources/org/activiti/db/upgrade/activiti.mysql.upgradestep.514.to.515.history.sql

@@ -101,5 +101,5 @@ alter table ACT_HI_TASKINST
     add TENANT_ID_ varchar(255) default '';      
     
 alter table ACT_HI_ACTINST
-    alter column ASSIGNEE_ varchar(255);
+    MODIFY ASSIGNEE_ varchar(255);
 

modules/activiti-engine/src/main/resources/org/activiti/db/upgrade/activiti.mysql55.upgradestep.514.to.515.history.sql

@@ -23,4 +23,4 @@ alter table ACT_HI_TASKINST
     add TENANT_ID_ varchar(255) default '';
     
 alter table ACT_HI_ACTINST
-    alter column ASSIGNEE_ varchar(255);
\ No newline at end of file
+    modify ASSIGNEE_ varchar(255);
\ No newline at end of file

modules/activiti-engine/src/main/resources/org/activiti/db/upgrade/activiti.oracle.upgradestep.514.to.515.history.sql

@@ -19,4 +19,4 @@ alter table ACT_HI_TASKINST
     add TENANT_ID_ NVARCHAR2(255) default '';    
     
 alter table ACT_HI_ACTINST
-    alter column ASSIGNEE_ NVARCHAR2(255);
\ No newline at end of file
+    modify ASSIGNEE_ NVARCHAR2(255);
\ No newline at end of file

modules/activiti-engine/src/main/resources/org/activiti/db/upgrade/activiti.postgres.upgradestep.514.to.515.history.sql

@@ -19,4 +19,4 @@ alter table ACT_HI_TASKINST
     add TENANT_ID_ varchar(255) default ''; 
     
 alter table ACT_HI_ACTINST
-    alter column ASSIGNEE_ varchar(255);
\ No newline at end of file
+    alter column ASSIGNEE_ TYPE varchar(255);
\ No newline at end of file