.gitingnore: set root path for binary names

- some directories containing the binary name (e.g., kamailio like in
  utils/kamctl/dbtext/kamailio/...) in path were ignored. Updated
  .gitignore to use /kamailio and /ser which according to manual should
  match on the root folder of GIT tree

.gitignore

@@ -10,8 +10,8 @@ modules.lst
 # ignore dependency files
 *.d
 # ignore binary files and objects
-ser
-kamailio
+/ser
+/kamailio
 *.so
 *.so.*
 *.o
@@ -38,4 +38,4 @@ utils/pdbt/pdbt
 libiname.lst
 *.dylib
 # man pages
-*.7
+*.7