Don't preload popular libraries, it conflicts with Bundler.

NEWS

@@ -21,6 +21,11 @@ Release 2.2.15
    Thanks to Potamianos Gregory for reporting this issue. Issue #500.
  * [Nginx] Default Nginx version changed to 0.7.66
    The previous default version was 0.7.65.
+ * Fixed more Bundler problems
+   Previous versions of Phusion Passenger would preload some popular
+   libraries such as mysql and sqlite3 in order to utilize copy-on-write
+   optimizations better. However this behavior conflicts with Bundler
+   so we've removed it.
 
 
 Release 2.2.14

lib/phusion_passenger/spawn_manager.rb

@@ -79,15 +79,6 @@ def initialize
 			require 'phusion_passenger/html_template'
 			require 'phusion_passenger/platform_info'
 			require 'phusion_passenger/exceptions'
-
-			# Commonly used libraries.
-			['mysql', 'sqlite3'].each do |lib|
-				begin
-					require lib
-				rescue LoadError
-					# Do nothing; ignore if not present.
-				end
-			end
 		end
 	end