Fix #11571: Versions 1.1 and 1.10 are treated as duplicates

A problem was discovered on manage_proj_edit_page.php where if versions
1.1 and 1.10 were both shown, clicking 'edit' for 1.1 would bring up the
edit version page for the 1.10 version instead.

This is due to an incorrect version name comparison in version_get_id
whereby the following check between strings was occurring:

if( "1.1" == "1.10" ) { ... }

PHP evaluates this expression to true because 1.1 and 1.10 are treated
as floats. We however need to preserve the string type during this
comparison, thus we need to use the === comparison operator instead.

core/version_api.php

@@ -490,7 +490,7 @@ function version_get_id( $p_version, $p_project_id = null, $p_inherit = null ) {
 	}
 
 	foreach( $g_cache_versions as $t_version ) {
-		if(( $t_version['version'] == $p_version ) && ( $t_version['project_id'] == $c_project_id ) ) {
+		if(( $t_version['version'] === $p_version ) && ( $t_version['project_id'] == $c_project_id ) ) {
 			return $t_version['id'];
 		}
 	}