Finished up some queries that are left hanging when an early exit is made....

Finished up some queries that are left hanging when an early exit is made. This was causing weirdness when fetching supercontigs and projecting them. ENSCORESW-429

modules/Bio/EnsEMBL/DBSQL/AssemblyMapperAdaptor.pm

@@ -609,6 +609,7 @@ sub register_component {
   if($sth->rows() == 0) {
     #this component is not used in the assembled part i.e. gap
     $asm_mapper->register_component($cmp_seq_region);
+    $sth->finish();
     return;
   }
 
@@ -618,6 +619,7 @@ sub register_component {
   #   chromosome:EquCab2|contig ( use '|' delimiter for 1-1 mappings )
   #
   if($sth->rows() != 1) {
+    $sth->finish();
     throw("Multiple assembled regions for single " .
           "component region cmp_seq_region_id=[$cmp_seq_region]\n".
           "Remember that multiple mappings use the \#-operaator".