[latexila] Tab label tooltip: "Main file" -> "Project main file"

[Sébastien Wilmet <swilmet src gnome org>]

commit 67463e9026b4c948e3612b58016d766544604126
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Sun Aug 6 13:31:33 2017 +0200

    Tab label tooltip: "Main file" -> "Project main file"
    
    To make it clearer.

 src/document_tab.vala |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/document_tab.vala b/src/document_tab.vala
index 542e7ca..c82674c 100644
--- a/src/document_tab.vala
+++ b/src/document_tab.vala
@@ -213,9 +213,9 @@ public class DocumentTab : Tepl.Tab
             return;
 
         if (project.main_file.equal (document.location))
-            _label.tooltip_markup += "\n<b>" + _("Main File") + "</b>";
+            _label.tooltip_markup += "\n<b>" + _("Project main file") + "</b>";
         else
-            _label.tooltip_markup += "\n<b>" + _("Main File:") + "</b> "
+            _label.tooltip_markup += "\n<b>" + _("Project main file:") + "</b> "
                 + get_main_file_relative_path ();
     }