Pull conditional out of begin block

Library/Homebrew/formula_installer.rb

@@ -154,16 +154,17 @@ class FormulaInstaller
 
     @@attempted << f
 
-    begin
+    if pour_bottle?(:warn => true)
-      if pour_bottle? :warn => true
+      begin
         pour
+      rescue => e
+        raise if ARGV.homebrew_developer?
+        @pour_failed = true
+        onoe e.message
+        opoo "Bottle installation failed: building from source."
+      else
         @poured_bottle = true
       end
-    rescue => e
-      raise e if ARGV.homebrew_developer?
-      @pour_failed = true
-      onoe e.message
-      opoo "Bottle installation failed: building from source."
     end
 
     build_bottle_preinstall if build_bottle?